Really really fun and enjoyable. The bullet physics were just the right amount of unwieldy yet predictable that made it very satisfying once you beat the level.
I did just want to say that I flew up very high on the fourth level and when I came back down I clipped through the floor. The sensei kitty text box appeared, but there was no text inside and the button did nothing. I had to restart the entire game. It really didn't bother me, but I just wanted to let you know.