I developed an entire game (speedrun style) during a live stream. Planned, programmed, designed, styled, voice acted, and sourced audio in just over 6 hours. After which Fast Go Fast was born, a lowrez dodge game where you play as a block, avoiding other blocks, while accelerating to ludicrous speed. It is a "simple" game, but I put as many features a game like this could have. I made sure to keep it stylistically interesting, doing the art for block generation by hand. The game saves high scores and allows them to be shared with others.
The game itself, after adding the music, turned out to be 178MB in size, because I refuse any game I made to loop audio during gameplay.