Pretty cool game! :)
I like these puzzle that links everything together :) My only question would be related to the ending; I read a sign saying I should go back to the beginning when I completed the, yet I didn't find what to do there.
I also found a small bug that kept me form searching further than I wished : when I managed to get my cube higher than the screen limits, the cube simply disappeared (clearing the memory) but did not respawn. I got stuck there and I couldn't do anything.
It's a pretty fun game despite that small problem ;) The simple design and music are just enough to be clear without being invasive or distracting. Good job overall!