Edit: v0.5.0 is out under the name Blocky Dungeon, so I put this one to 1 star.
Original: 3 stars while still an early unfinished version of the game.  I love it conceptually, and it will probably be tons of fun when completed.  The visuals need to be improved, I can't tell which walls will become open when the block lands.  The performance is also poor (seems to get worse over time), which makes the controls unresponsive.