DEV Community: sun jack

Contra (NES): The One-Hit-Death Co-op Classic That Made the Konami Code Famous

sun jack — Mon, 26 Oct 2026 03:01:30 +0000

There's a specific kind of silence that falls over a room when two people are on the Waterfall stage of Contra and one of them is climbing too fast. If you grew up with an NES, you probably know it. Konami's run-and-gun is hard, it's fast, one hit kills you, and it's still one of the best co-op games ever made. You can play Contra (NES) in your browser here with no download, and below is why it's worth another look in 2026.

Background: From Arcade Cabinet to Living Room

Contra started as a Konami arcade game in 1987. The NES version came out in 1988, and it wasn't a cut-down port. Konami reworked it for home play, and it became the version most people remember.

The setup is simple, with a lot of '80s action movie in it. Two commandos, Bill Rizer and Lance Bean, are sent in to stop an alien force called Red Falcon. You fight through jungle, enemy bases, waterfalls, snowfields and machinery, and eventually reach something very organic and very alien. The story is thin, and that's fine, because Contra is about the next three seconds of survival.

Gameplay: Eight Stages, One Hit

The NES version has eight stages:

Jungle
Base 1
Waterfall
Base 2
Snow Field
Energy Zone
Hangar
Alien's Lair

Most of them are side-scrolling run-and-gun. You run, jump, fall through platforms and shoot in eight directions. The Waterfall stage scrolls vertically instead. The two Base stages switch to a behind-the-back view, where you push forward into the screen, destroy wall cores and dodge rolling grenades.

One hit costs a life, every time. There's no health bar, so learning each stage is the whole game. At first enemies seem to show up at random, but by the third attempt you know exactly where the next sniper is hiding.

Highlights: What Still Holds Up

The weapons. Flying capsules and pillbox sensors drop power-ups marked with a letter:

M: Machine Gun (hold to auto-fire)
F: Fire Ball (slow, curving shots)
L: Laser (a single piercing beam)
S: Spread Gun (five shots in a fan)
R: Rapid Fire (makes your bullets faster)
B: Barrier (brief invincibility)

The Spread Gun is legendary for a reason. It covers so much of the screen that it changes how the game plays. When you die you drop back to the basic rifle, so losing an S at the wrong moment hurts.

Two-player simultaneous co-op. Contra was built for two people on one couch. You share the screen and the scrolling, so you're working together and quietly competing at the same time. That's where the Waterfall stage tension comes from.

The Konami Code. On the title screen, enter ↑ ↑ ↓ ↓ ← → ← → B A, then press Start, and you begin with 30 lives instead of 3. It's arguably the most famous cheat code in gaming, and Contra is where a lot of players first learned it. No shame in using it.

Beginner Tips

Use the Konami Code. Seriously. Get through the stages first, then go for a clean run.
Protect the Spread Gun. Once you have S, play more carefully. Hanging onto it makes the later stages much more manageable.
Shoot diagonally. Many enemies sit above or below you. Holding up or down while moving lets you fire at angles without stopping.
Don't rush the screen. Enemies often spawn from the edge you're moving toward. Moving a little slower gives you time to react.
On the Waterfall, climb together. In co-op, the player who climbs ahead can scroll the screen and leave their partner behind. Agree on a pace.
In the Base stages, watch for the grenades. The rolling ones are easy to miss while you're focused on the core. Jump them, then fire.

Under the Hood (for the Devs Here)

Full disclosure: I built OnlineClassicGame, the site the links above point to. The previous posts covered the overall stack, arcade romsets and PS1 core fallback. This time I want to talk about something less glamorous: working out what file you've actually got before you hand it to an emulator.

The emulation itself runs on Nostalgist.js, which wraps RetroArch's WASM cores. In my SYSTEM_TO_CORES mapping, NES goes to nestopia. The hard part isn't running the core. It's that ROM files in the wild are a mess. The same game can arrive as a raw ROM, a zip or a 7z archive, and the extension doesn't always tell the truth.

So my rom-loader.js doesn't trust the filename. It reads the first few bytes and sniffs the magic number. These are the kinds of signatures involved:

50 4B 03 04 (PK..) means a zip container
37 7A BC AF 27 1C means 7z
4E 45 53 1A (NES + 0x1A) is the iNES header, so it's a raw NES ROM

Based on that, the file gets routed. Zips are extracted with fflate, 7z archives go through 7z-wasm, and raw ROMs pass straight through. One painful lesson: 7z-wasm uses an in-memory filesystem (MEMFS), and if you don't clean it up between loads, files from a previous game can leak into the next extraction. Keeping every load isolated from the last one had to be handled explicitly.

The other rule is that the sniffing logic must know when not to decompress. Arcade cores like FBNeo need the romset zip intact (that was the Metal Slug post). An NES cartridge like Contra, though, is happiest as a bare .nes file.

Your Turn

Contra on NES was many players' first taste of real difficulty, and it still holds up. If you give Contra a run in your browser, I'd love to know: did you beat it without the Konami Code, and which stage gave you the most trouble?

Tekken 3: The PlayStation Fighter That Taught a Generation to Sidestep

sun jack — Wed, 21 Oct 2026 01:08:41 +0000

Ask anyone who owned a PlayStation in the late '90s to name a fighting game, and there's a good chance the answer is Tekken 3. Namco's 3D fighter hit arcades in 1997, landed on the PlayStation in 1998, and went on to sell more than 8 million copies on the console, making it one of the best-selling fighting games of its era.

👉 Play Tekken 3 in your browser (free, no download or sign-up)

A Fresh Start for the Series

Tekken 3 jumps nearly two decades ahead of Tekken 2, which meant most of the cast was brand new. Heihachi Mishima is back, older and still scheming, but the spotlight belongs to a new generation:

Jin Kazama, Kazuya's son, raised by Heihachi and out for revenge
Ling Xiaoyu, a fast, tricky fighter who quickly became a fan favorite
Hwoarang, the Taekwondo hothead with relentless kick strings
Eddy Gordo, whose capoeira style made him the go-to pick for button mashers everywhere
Bryan Fury, Forest Law, Julia Chang and more

The main villain is Ogre, an ancient being that has been hunting the world's best martial artists. Veterans like Paul, Nina, Yoshimitsu, King and Lei return too, and the hidden roster goes deep, with characters unlocked by beating Arcade mode again and again.

The Big Change: Sidestepping

Earlier Tekken games were 3D in looks but mostly 2D in how you moved. Tekken 3 changed that. By tapping up or down, you can sidestep into or out of the background, dodging straight attacks and opening up your opponent for a counter.

It sounds small, but it shifted the whole game. Linear attacks became risky, movement became a real skill, and matches felt like they happened in a space rather than on a line. Jumping was also toned down, which pushed players toward ground game and footwork.

How It Plays

Tekken's control scheme is still one of the most intuitive in fighting games: four buttons, one for each limb. Left punch, right punch, left kick, right kick. Press the button for the limb you want to move, and the character does exactly that.

A few core ideas carry most of the game:

Blocking is done by holding back (or down-back for low attacks)
Throws can't be blocked, but they can be escaped with the right button
Juggles are the heart of high damage: launch your opponent into the air, then keep hitting them before they land
10-hit strings let you practice long, memorized combos for big payoffs

The result is a game where you can have fun on day one, but still find new depth years later.

More Than Just Arcade Mode

The PlayStation version was packed with extras that made it worth owning, not just renting:

Tekken Force, a side-scrolling beat 'em up mode
Tekken Ball, a ridiculous volleyball-style mini-game
Gon, a tiny fire-breathing dinosaur exclusive to the home version
Practice mode for learning combos and move lists
A Theater mode to rewatch character endings

Tips for First-Timers

Pick one character and stick with them. Paul and Jin are great for learning fundamentals.
Learn one launcher and one follow-up juggle. That alone will win you a lot of matches against the CPU.
Sidestep straight attacks instead of always blocking.
Don't be afraid of Eddy. He looks unstoppable, but his patterns are easy to read once you block a few times.

Under the Hood (for the Devs Here)

Full disclosure: I built OnlineClassicGame, the site linked in this post. My last two posts were about arcade games, so here's something different: PlayStation emulation in the browser.

The site runs RetroArch cores compiled to WebAssembly, loaded through Nostalgist.js. For PlayStation games I ended up with a primary and a fallback core:

mednafen_psx_hw as the default, for accuracy
pcsx_rearmed as the fallback, which is lighter and more forgiving on weaker devices

That setup came from a simple lesson: what runs perfectly on a desktop browser doesn't always run on a mid-range phone. Having a fallback makes the difference between "slightly less accurate" and "doesn't load at all." The front end is plain vanilla JavaScript (ES Modules) and Tailwind CSS, with no build step.

Give It a Try

Whether you spent your childhood mashing with Eddy or practicing Jin's electric wind god fist, Tekken 3 still holds up as one of the most fun 3D fighters ever made.

🎮 Play Tekken 3 online

Who was your main? Let me know in the comments.

Metal Slug (1996): The Hand-Drawn Arcade Run-and-Gun That Still Holds Up

sun jack — Mon, 12 Oct 2026 08:28:26 +0000

Some games you remember for their story. Metal Slug you remember for the explosions, and for the fact that every single frame of them was drawn by hand.

Released in arcades in 1996 on SNK's Neo Geo MVS, Metal Slug (subtitled Super Vehicle-001) was developed by Nazca Corporation, a small studio founded by former Irem developers. It became the start of one of the most loved run-and-gun series ever made.

👉 Play Metal Slug in your browser (free, no download or sign-up)

The Setup

You play as Marco Rossi or Tarma Roving of the Peregrine Falcon Squad. General Morden and his Rebel Army have launched a coup, and the military's newest weapon, the SV-001 "Metal Slug" tank, is caught up in the chaos. Your job is to fight through the Rebels, get the Slug back and take Morden down.

That is about all the story you need. The game spends its energy on six missions packed with jungles, ruined towns, snowy mountains and heavily fortified Rebel bases, each ending in a huge boss fight.

How It Plays

The controls are about as simple as arcade games get: move, shoot, jump and throw a grenade. Everything else comes from what you pick up and how you survive.

Weapons: You start with a basic pistol, but rescued prisoners drop power-ups like the Heavy Machine Gun, Rocket Launcher, Flame Shot and Shotgun. Each has limited ammo, so you are constantly swapping.
Knife attacks: Get close to an enemy and the fire button turns into a melee slash, which hits hard.
Prisoners (POWs): Tied-up bearded prisoners are scattered through every mission. Free them for points and item drops.
One-hit deaths: A single bullet kills you, so the game rewards learning enemy patterns and keeping on the move.
Two-player co-op: A second player can join at any time, which turns the game into glorious chaos.

The Metal Slug Itself

The tank is the star of the show. When you find one, you can jump in and suddenly you have a vulcan cannon that aims independently of the direction you move, plus heavy cannon shells for anything big. It can take a few hits before it is destroyed, and getting out just before it blows up is a skill every regular learned the hard way.

Later games added planes, camels, mechs and more, but the original tank is still the most iconic vehicle in the series.

Why the Art Still Holds Up

The pixel art is what made Metal Slug famous, and it has aged far better than most 3D games from the same era.

Every soldier, explosion and bit of debris is hand-animated. Rebel soldiers chat, cook over campfires and panic when they spot you. Enemies scream and run, buildings crumble piece by piece, and bosses fall apart in stages. Add the famous voice shouting "Heavy Machine Gun!" when you grab a power-up, and it is easy to see why so many people still remember it.

It is also genuinely funny. The game takes its war setting about as seriously as a Saturday morning cartoon, and that tone carried through the whole series.

Tips for First-Timers

Free every POW. The items they drop are your main source of better weapons.
Use the knife. Up close it deals more damage than most guns.
Keep moving. Most deaths come from stray bullets, not from bosses.
Save grenades for bosses and for enemies behind cover.
Bring a friend. Co-op makes the harder missions much more manageable, and twice as fun.

If you get hooked, the rest of the series is waiting: Metal Slug 2, X and 3 are widely considered the high point of the franchise.

Under the Hood (for the Devs Here)

Full disclosure: I built OnlineRetroGame, the site linked in this post. Since this is DEV, here is one thing that building it taught me about arcade games.

A console game is usually a single ROM file. A Neo Geo game like Metal Slug is not: it is a romset, several ROM chip dumps packed into one zip, and the arcade emulator (FinalBurn Neo, compiled to WebAssembly) expects to receive that zip exactly as-is.

My loader normally sniffs each file's magic bytes to detect its real format and unpacks archives in the browser before handing them to the emulator. Arcade romsets have to skip that step and be passed through untouched, otherwise the emulator cannot find the chips it is looking for. It is a small detail, but it caused a lot of "why won't this boot?" moments.

On phones and tablets, an on-screen gamepad turns taps into keyboard events, so the same emulator setup works on desktop and mobile.

Give It a Try

Whether you pumped coins into this cabinet in the '90s or you have never seen it before, Metal Slug is still one of the best 20-minute arcade experiences around.

🎮 Play Metal Slug online

Did you ever beat it on one credit? Tell me in the comments.

The King of Fighters '97: The Orochi Saga Finale That Never Left the Arcade

sun jack — Mon, 12 Oct 2026 07:13:03 +0000

If you spent any time in an arcade in the late '90s, especially in Asia, there's a good chance The King of Fighters '97 was the cabinet with the biggest crowd around it. Released by SNK on the Neo Geo MVS in 1997, it closed out the Orochi Saga and went on to become one of the most-played fighting games of all time.

👉 Play The King of Fighters '97 in your browser (no download or install needed)

The Story: Closing the Orochi Saga

KOF '97 is the third and final chapter of the Orochi Saga that began in KOF '95. The tournament has grown into a worldwide televised event, and that huge audience is exactly what Orochi's remaining followers have been waiting for.

At the heart of the story are the three clans that sealed Orochi away long ago: Kyo Kusanagi, Iori Yagami and Chizuru Kagura. The trouble is that Kyo and Iori can barely stand to be in the same room. The newcomers of the New Faces Team (Yashiro, Shermie and Chris) turn out to be far more than a rock band, and the ending, where two bitter rivals are forced onto the same side, is still one of the most memorable moments in the series.

Gameplay: Two Modes, One Classic

The core is the classic KOF format: pick three fighters and battle another team of three, or play one-on-one in Single mode. Each character uses four buttons: light punch, light kick, heavy punch and heavy kick.

The big addition in '97 is the choice between two fighting systems:

Advanced Mode builds on KOF '96. You get dashes, short hops, rolls and a power gauge that stores up to three stocks, which fill up as you attack and defend. Spend a stock on a super move, or press A+B+C to enter MAX mode for a powered-up window.
Extra Mode brings back the KOF '95 feel. You charge your power gauge by hand, dodge in place instead of rolling, and once your health bar starts flashing red you can fire off desperation moves freely.

Advanced Mode is faster and more combo-friendly; Extra Mode is slower and more about reading your opponent. Having both in one game is a big part of why '97 kept players coming back.

The Roster

All the series favorites are here: Terry, Andy, Joe and Mai from Fatal Fury, Ryo and Robert from Art of Fighting, the Ikari Warriors with Leona, Athena's Psycho Soldier team, and more. New for this year:

Shingo Yabuki, Kyo's enthusiastic (and very self-taught) would-be student
The New Faces Team: Yashiro Nanakase, Shermie and Chris
A Special Team of Fatal Fury guests: Billy Kane, Ryuji Yamazaki and Blue Mary
The Sacred Treasures Team: Kyo, Iori and Chizuru, finally standing together

Then there are the hidden fighters that every arcade regular whispered about: Orochi Iori and Orochi Leona (both consumed by the Riot of the Blood), awakened versions of the New Faces Team, and the final boss himself, Orochi.

Why People Still Play It

KOF '97 became a phenomenon in China and Hong Kong in particular. Arcades kept their cabinets running for years after newer games came out, and there is still an active competitive scene today. Its engine is fast and easy to read, and even its famous quirks and glitches have become part of the culture around it.

SNK clearly knows it too: the game was re-released in 2018 as The King of Fighters '97 Global Match for modern consoles and PC, more than twenty years after it first hit arcades.

Tips for First-Timers

Start in Advanced Mode. Rolls and stored power stocks make it more forgiving for new players.
Roll with A+B to escape pressure or get behind a slow attack.
Learn one simple combo per character, for example a jumping heavy attack into a crouching light kick into a special move.
Pick a balanced team. Kyo, Iori and Terry are all great characters to learn the basics with.

Default keyboard controls on the browser version: arrow keys to move, Z / X / A / S for the four attack buttons, Enter to start and Right Shift to insert a coin. On phones and tablets an on-screen gamepad appears automatically.

How It Runs in a Browser (for the Devs Here)

Full disclosure: I built OnlineClassicGame, the site linked in this post. Since this is DEV, a quick look under the hood:

The arcade version runs on FinalBurn Neo compiled to WebAssembly, loaded through Nostalgist.js (a lightweight wrapper around RetroArch's web build).
The front end is plain vanilla JavaScript (ES Modules) + Tailwind CSS, with no build step.
On touch devices, a virtual gamepad translates taps into keyboard events, so the same emulator setup works on desktop and mobile.

Happy to answer questions in the comments if you're building something similar.

Give It a Try

Whether you're coming back for nostalgia or meeting Kyo and Iori for the first time, '97 is still one of the best ways to see what made SNK's fighters special.

🎮 Play The King of Fighters '97 online

Which team did you always pick? Let me know in the comments.