The game fits the theme really nicely! It is also a very nice puzzle that I've actually enjoyed! Although the game lacks a couple of things (That's in genral, you probably wouldn't have been able to make all them in 7 days):
-- Some music is definitely needed. Would make the game a lot more enjoyable. Even some really simple songs would instantly make it better (for me at least)
-- Some arrows that show your movement and then reversed for better understanding of the game.
--Maybe a tutorial for introducing the player to the concept
--Adding new interesting mechanics throughout the game. Something I thought of: Blocks that can be pushed but which will block you if something is in the way or active enemies which are timed to your movements.
Overall the game is very interesting to play and I think if you work more on the concept you could probably release it on mobile.