I liked it, controlled well and there was a lot of variety in the upgrades- each upgrade made me wonder what would happen visually to the character, making me play on ;P
The last two bosses were way too easy though, I focused on getting more bullets, faster fire rate and damage which lead to the bosses getting killed instantly- I understand why as it's hard to balance a game with upgrades involved ;P Oh- and a fickle thing- the bosses didn't have many differences from normal enemies- I think it would be interesting to have bosses that would protect themselves more/ have key parts to aim at.
Other then that- a pretty good bullet hell :P