Very fun and quick game. I think you should change the IJKL keybinds to the arrowkeys, however. People are more familiar with those keys and it would take away from the frustrating difficulty of using a completely new set of keys. Great art style! Everything looks simply pixelated and flat, but the style has much more depth through use of the gradients and textures. The clean, high-fps animations also do it justice, as it's a new modern form of game.
All of that being said, it's not perfect. It's a great iteration of the older concept of using two-hands, but for those who have just attempted, it's frustrating. This is capable of being great, though! You have a great idea on your hands, and if you improved it- this can be a great single player AND co-op game like the flash bmtron game!