I'm a big fan of this! The mechanics are really simple but through clever enemy and level design you manage to cram a lot of different game-feels into one game. It evoked, at various times for me, Kid Icarus, Frogger, and Metroid, while really being its own unique thing.
Era Feel-wise, musically and level design it really nails NES vibes, although the sprites are just a little too "nice" (big, vibrant colors, good shading). Maybe it evokes an arcade cabinet of that era though.
Audio design I just wish it had more than one music track :) It was a great track but after a certain number of loops I was just wishing for variety.
All-in-all a really solid entry, one of the best I've played. Great stuff!