I'm guessing this will likely be the simplest submission for the jam, but here it is. I wanted to make as small of a game as possible using just Javascript and HTML, and it ended up being 2.5 kilobytes zipped (~4 kilobytes unzipped). It made more sense to me that Collins wouldn't want to completely use up all of the guidance computer's storage just for a game, so a smaller game that could (theoretically) fit alongside the gc code would be more feasible.
The game itself is built using 2D matrices to track positions of different ASCII characters, with movement simulated by moving the characters across the rows/columns of the matrix. I ended up saving a lot of space by using programmatic sound effects via the AudioContext web API rather than using mp3 sound files, which was pretty cool to learn. Also, getting the jumps in the game to feel somewhat "moon-like" was sorta fun, and I think make it a bit more challenging.
Anyways, the source code is all available here: https://github.com/benbusby/tiny-moon-runner. Looking forward to seeing everyone else's (likely more complicated) submissions!