The sounds mixed well with the graphics, I really liked that.
The controls were unusual, but interesting... I Just missed a pause button during the stage.
Some bullets for the enemies would be nice and would make the "No-Damage" powerup more valuable.
The size of the game felt nice and I liked the base difficulty, but it could have had another mechanic that made things a little more challenging... Like dodging.
And some story objectives or a boss to close the experience...
Overall it was interesting.