This is definitely good
I had a hard time at first but it seemed to be easy to catch on to. My only gripe was the playing field was a bit small (I know it's like Tetris) and the bugs stated before me.
I found myself jumping around like a madman, wall jumping and climbing up the blocks before they even hit the ground. It was very hard to be ninja like though when the game didn't support it, i.e. I would constanly get squashed when I was on top of a block that was resting, as well as falling through some blocks on the floor or wall.
This was an extremely good attempt, and I'm not saying it was easy to program in the first place but I'm confident when you make the second on it will be bigger and more user-friendly. Kudos and thanks for the great game.