Oh shoot! Talk about knocking it out of the park! This a very well constructed game to say the least. Definitely feels like an NES game from the 80s; brutally difficult, constantly respawning enemies, and simple d-pad + 2 button action (also native controller support? Fuck yeah!!!). Unfortunately, I'm not the best at these tough as nails games so I couldn't get any farther than the second checkpoint (even on baby difficulty) but so far everything seems solid and controls well (especially with a dedicated controller), and, most importantly, is fun.
All that being said, I did notice a few quirks while briefly playing the game, one strange bug I noticed is some sort of positioning errors going on the bridge after the first checkpoint. If you just hold left on the bridge your character will jitter a bit, he'll still make it across the bridge without a problem, but it should still be noted as I don't think that was intentional. Another bug I stumbled upon was if you died to an enemy but then the enemy knocks you into a spike pit you'd die again before going back to your checkpoint. Not a huge deal but like I said before worth noting. All and all though, not bad at all a few small bugs here and there but nothing bad. Excellent work!