Hello! Fun game, I would say first of all that the style of trying to replicate NES games was executed well here, I really liked the crunched up quack sound effect for example. The visuals also worked well here and although I personally find chiptune music to be a bit annoying in general, considering the limits you had to abide by, it worked pretty well here.
Some critiques I would have however are that the game itself felt pretty unresponsive. The basic movement feels good, but the base attack takes a bit too long to do for my liking and it was hard to tell when the enemies were actually dead. It also took a while to figure out that I had to attack the first lever to progress in the level, and after that I couldn't figure out where I was supposed to go so I stopped playing after that.
Otherwise, I think the concept is pretty fun and I really like the idea of a duck-themed metroidvania and to the scope of the jam, I would say it was done pretty well. Nice entry!