I do like the idea, though I agree with the previous comment about the game essentially playing itself at points, which largely comes down to the limited possible spawn points for enemies; it may have been better to let them spawn in a wider range of offscreen locations, because standing in the starting position causes them to form two single file lines going headfirst into your deflected bullets. Imo the two possible mechanical alterations that I would enjoy are either that you have to aim to deflect bullets back at your enemies, or to just zoom in the screen a bit and focus only on the melee combat. I actually felt that strafing around enemies in melee mode while in the middle of the fray was pretty enjoyable (especially with the variety of enemies you have), but the fact that I could switch to a shield at any moment to turn it to easy mode undermined that satisfaction a bit.
I did also enjoy the soundscape, and the sprites are pretty fun as well. Congrats on your entry!