Thoughts from playing:

• Audio balance is skewed towards the left speaker.
• Love the presentation. Fun backstory, excellent character designs.
• Gameplay is fun and solid. Reminds me of Binding of Isaac.
• The boss didn't seem to behave properly. It looks like it's supposed to stop and flash the shadow when it's going to drop down, but sometimes it just drops down with no chance to dodge it.
• After losing to the boss and resetting I can't leave the tutorial rooms.

The graphics was fun, the game play entertaining and I immersed myself so much that it didn't feel like a 64x64 game!

Very good job!

Nice game. 

I really enjoyed the graphics, really nice use of pixel limitations and clean finish. Some nice progression of difficulty also. Took me a while to get the hang of the controls as I was getting shoot direction mixed up with movement direction even in the more difficult rooms after playing for a while, but that's more of a reflection on my brain than on your game. 

Maybe I missed it, but would have been nice to get life recover items/bonus items to help and difficulty increased?

Nice game.