The short answer
The most common game development mistakes are making the scope too big, skipping a playable prototype, playtesting too late, leaving marketing until launch and underestimating polish and bug fixing. Each one is avoidable with the same habits: cut the idea to its smallest fun version, prove the core loop with grey boxes, put the game in front of strangers every few weeks, and plan the launch from the first month.
1. The scope is too big
The classic mistake. A first project planned as an open world with crafting, story and multiplayer rarely ships. Fix: define the smallest version that is still fun, finish it, then grow it with updates.
2. No prototype of the core loop
Teams commission art, write lore and build menus before knowing whether the main action is enjoyable. Fix: build a grey-box prototype first and do not move on until people enjoy it with placeholder shapes. See our game prototyping guide.
3. Adding features instead of finishing
New ideas feel more exciting than the last 20% of the work. Fix: keep a "later" list. Ideas go there unless they fix a problem testers actually had.
4. Playtesting late, or only with friends
Friends are kind, and developers know where everything is. Fix: watch strangers play without helping them, every few weeks, from the prototype onwards. Where they get lost is where the game needs work.
5. Building multiplayer after single-player
Networking changes how almost every system is written. Adding it at the end usually means rebuilding the game. Fix: if the game will be multiplayer, prototype it online from day one. Our article on what a multiplayer FPS costs explains why.
6. Ignoring low-end devices
A game that runs well on the developer's laptop or flagship phone may stutter on the devices most players own. Fix: pick a minimum device early, test on it every week and use the engine's profiler. Unity's documentation recommends profiling on the target device rather than in the editor.
7. No version control
One corrupted file or bad change can cost weeks. Fix: use version control such as Git or Unity Version Control from the first day, with off-site backups.
8. Starting marketing at launch
On Steam, wishlists collected before launch drive release-day visibility, and players cannot buy a game they have never heard of. Fix: publish a store page early, share progress, and build a list of interested players months before release. Our indie marketing guide and Steam wishlists guide show how.
9. Treating launch as the end
Most successful games improve after release with fixes, content and events. Fix: keep budget and people for the first three months after launch. See LiveOps.
10. No analytics
Without data you cannot tell where players quit or what they buy. Fix: add a basic analytics tool before soft launch and track tutorial completion, level progress and retention. Our mobile game KPIs guide lists what to measure.
11. Contracts that do not transfer the code
Some outsourcing agreements leave the source code or rights with the contractor. Fix: make sure the contract assigns all IP and delivers the full source on payment. Our guide on choosing a studio covers the questions to ask.
12. Underestimating polish and bug fixing
The last stretch, from "it works" to "it feels finished", routinely takes as long as the first playable version. Store submission adds its own checks. Fix: plan explicit polish time and read our store submission checklist before you need it.
Warning signs your project is in trouble
- The release date has moved more than once and nobody can say what is left to do.
- There is no build that someone outside the team can play today.
- New features keep arriving while old bugs stay open.
- Nobody has looked at performance on the minimum target device in weeks.
- There is no store page, trailer or community a month before launch.
Any one of these is fixable. Several at once usually mean the scope needs cutting now, before the budget runs out.
A pre-production checklist
Most of the mistakes above are decided before production starts. Before committing a budget, make sure you can answer yes to each of these:
| Question | Why it matters |
|---|---|
| Is the core loop proven fun in a playable prototype? | Everything else depends on it |
| Is the scope written down, with a "later" list for extra ideas? | Stops scope creep before it starts |
| Are target platforms and a minimum device chosen? | Shapes art, performance and testing |
| Is multiplayer in or out, decided now? | Adding it later is a rebuild |
| Is there a milestone plan with a playable build at each milestone? | Makes progress visible and budget predictable |
| Who owns the code, art and IP, in writing? | Protects you if the team changes |
| When does marketing start, and who does it? | Launch visibility is built months earlier |
How studios avoid these
Experienced teams use the same safeguards: milestone plans with a playable build at every milestone, weekly builds the client can try, outside testers, and a launch plan from the start. That is how we run projects; see co-development or outsourced game development.
Sources: GDC Vault: conference talks and postmortems · Steamworks: visibility on Steam · Unity: performance profiling tips · Pro Git: about version control. Checked October 20, 2026.
Related: Co-development · Outsource game development · Get a quote
Originally published on A Plus Games Studio, a game, AR and VR development studio in Sacramento, CA.
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