A couple of things:
You can't turn to change direction without moving, making you an easy target for the enemies.
The enemies are tough, can kill you in 1 or 2 attacks, and on top of that you can miss. Either make the missing chance lower, or the enemies weaker (the first 2 floors at least). An enemy killed me in the first 3 moves, in only one shoot. This should not happen. Why would you play a game were the first enemy kills you in one shot? Is not a tutorial were you learn the "death mechanics", since there is none
Enemies follow you without even being in the same "room"
Besides those gameplay things, that can be fixed, the game seems nice. Goofy looking stuff, interesting power ups
EDIT:1. yep, there was a key to change direction... F me
2. not really, it was a new run. The enemy just obliterate me (unless the game keeps track of the time I had it open, not the current time of the current run)