Very simple mechanically.
The little monsters looked like they have no thoughts in those heads of theirs and I love themb.
Rotations were, by what I could tell, handled in a ways that stayed true to our dimensions for a GB screen. Though I'm not fully sure if the duck was supposed to fly farther if you were hit multiple times in succession or not, it was funny to watch them spin away.
The music was a jam, though it sounded more like what I'd expect from a DOS game (or maybe a GBA game) than a GB game. Very 16-bit feel. One of the instruments in the non-boss section sounded exactly like something I worked with when I was using OpenMPT a few years ago. I think it was a sawtooth wave? It's been a little bit. Though, it's worth noting that were weren't required per jam rules to make 8-bit music, so I don't count that against the soundtrack.
The pacing was on the slow side, but the music was jamming enough that really didn't bother me.
I think the boss wasn't causing me to drop ducks and just pushed me around? I mostly dodged stuff and the couple times I failed to I didn't lose the duck.
In all, a good, albeit goofy, entry.