Very Good.
I have just played this for like half an hour. This is a very addictive game. Good job on finding a concept like that! Kind of simple, yet so addicting! Smooth controls. The music fits with the game. I like how the background changes every time you play. Nice effects, i like how the triangle leaves all little triangles after him. Also, the screen control is very nice! I think the game might be just a bit more fun if you added additional stuff like items. But that doesn't really matter. You truly made a good game here! Keep this up.