Hello!
I finished the game! It was fairly simple but for what it was I liked it. I did however feel like maybe at some times I brute forced the puzzles by sending the blocks off-screen, especially on the last level. Maybe think about putting the flip function on mouse click instead of 'E' since you are already having to use the mouse for that function. You could even expand the flipping environment tile concept with a left click and right click with their own function depending on the colour of the tile, for instance swapping colours on right click for non-grey tiles. Adding more colours with unique effects could expand the concept too if you wanted to take it further. Overall a good minimalist platformer!
Our team have submitted a Cube game too! It's a runner that combines Tetris and precision platforming if you'd like to check it out (Link below). Would love to get some feedback if you have the time. :)
I wish you the best with your projects!
https://itch.io/jam/feedback-quest-8-indiegames-x-indie-streamers/rate/3773442