not bad, but it needs more. your basic engine works fine, but the game is a bit bland. power-ups, perhaps squares that move at diagonals or that shrink you, and maybe a score multiplier based on your size. try adding a bit more and you could have yourself a very fun game.
pretty much the exact same as the first game, and the upgrade system is worse. Really not an entertaining enough game to play a second time (already beat the first). 1/5 for wasting my time.
so, yeah, you can go straight through the walls. you should probably bother to play-test your POS games before posting them. thanks for the point though, it was easy to rate this 1/5 after just a few seconds.