It's kinda of incredible you got this game made in 3 days. Very well done indeed.
I love all the different music tracks and the chunky sound effects. The graphics is pretty simple, but very reminiscent and true to the vibe you were going for.
The mechanics is very clever. It's not the first game I have played this jam to have used this interpretation of the pause mechanics, but yours is very well implemented, and works bug-free. Not everything is spelt out for you so it was great discovering new interactions as you play.
I love how there's different kinds of enemies and even a boss fight. The boss fight is even designed with the key mechanics in mind.
The only thing I kinda dislike was how heavy the character felt when moving. Too much inertia when starting for me. Not sure if that's how NES games usually are since I didn't grow up on them, so maybe it's a nostalgia thing, but for this game I found it a bit clunky. There's some hidden areas where I couldn't find how to access it, but it didn't hinder the game progress.
Overall this is an amazing entry though. Great job!