This game is from the developer of rRootage, and is graphically similar and im some ways similar in gameplay. Rather than fighting boss characters, this game focuses on smaller 'entities' that move around the screen firing streams of shots.
In my opinion, this game could do with a boost in speed to give a bit more of a rush, but other than that it needs no improvement. The graphics, sound, and gameplay make this pure fun, perfect for killing a bit of time.
Definitely worth a look