This was a pretty fun, and fairly difficult bullet hell game!
I played on normal, because my pride wouldn't let me choose easy. I managed to complete the game, despite quite a few "game overs."
I liked both of the attack abilities. The time travel mechanic was pretty hard to use at first, and I found that it was mainly useful on the bosses. In the rooms teaming with enemies, I found that attempting the time travel to heal just left me in a worse situation than before each time. In fact, I found the enemy swarms on the last few floors harder than any of the bosses.
Nice work!