RET

I like it so far, though you could add some slight improvements: R-key for restart, p for pause/menu, m for mute, change the music-button to a musical note (now it looks like a settings button), and give falling platforms a different color, or give it some diagonal lines as if it were cracked, so it is distinguishable from others. It might also help if red blocks you can go through were bright red, while red blocks that stop you were a darker shade. Maybe switch level 1 and 2, where you learn red blocks are evil in level 1, and then get the new mechanic of the save-in-red-block in level 2. Also, some people might like using the wasd keys better. Good luck!