Fun: The game was fun but challenging. Overall good gameplay, but I got stuck in walls sometimes and had to restart, which was annoying. The final level was my favorite due to the fast paced gameplay.
Theme: Good use of the theme, and it's fun and satisfying to switch gravity, somewhat reminiscent of the Portal games. Occasionally it would boost me into walls and crash the game.
Twist: I like how the blocks change sprites when they run out, but a counter for how many switches one has left could be useful.
Overall fun, but a little buggy. This is expected for a game that was made in 3 days, so no worries :)