Thanks for the great feedback! We're glad you enjoyed it, and we appreciate the suggestions. We intentionally balanced the game to be on the easier side for the jam, since most people aren't willing to give a game more than about 5 minutes when judging submissions we deliberately made it so they could see basically the whole game in that time. We do intend on releasing a post-jam version with difficulty settings to mitigate this, but since this was built in 72 hours we didn't really have time.
Your suggestion about making the keys appear only after the room is cleared is a good idea, and we'll definitely try that out in the future. The idea of making the keys appear randomly is also worth experimenting.
Thanks again for the feedback and suggestions.