I like the look of it, very NES-y (love that you made a box-art too). The music is not quite as punchy as I'd like for the NES vibes though, and also the screen-shake when you hit an enemy feels too wavey and kind of ruins the old-school immersion for me.
I really like how distinct the three levels are visually, though I wish they were more distinct gameplay wise too. But overall its a pretty cool and good entry!