Damn! What a masterpiece. This game totally blew me away. The ambiance, the atmosphere, the smart use of 2d lights, the progressive music that builds when the game is about to end, the beautiful relation to the theme, the amazing sound design, the list just goes on and on. Minor details like nerves popping of the old brain's eyes while the young brain's eyes being clean were just the icing on the cake. This was a near-perfect entry and hands down the best game I've tried so far from the jam :)
However here a few minor suggestions that I have:
1. I got stuck at a few places and had to restart the entire game, wish there were checkpoints and a restart button.
2. The old brain's mouth was not animated as the younger one (Ik this is too much but I'm a sucker for these fine details XD) as they were speaking.
3. W for jump rather than space would have made life easier.
4. Need more gameplay pls XP