I love the aesthetic alot! Great job on the demons especially!
The sound design could use some work, I really didn't like the loud dings at the end of each wave. The fonts used both in the promotional work and in the game itself are pretty difficult to read, so you should try to use different ones next time. The acid demon also never aimed at me, which is probably a good thing since I couldn't see his bullets anyways. There's also some to be said about the amount of juice that needs to be added, ie knockback on enemies, etc, but I did like the flashing horns a lot.
The movement and combat feel good, and it was pretty well balanced to not be too difficult while also pushing me into a demon-infested corner. Great job on that aspect, and keep up the good work overall!