My first impression was moving to the left, grinning at the derpy walk cycle, and then chuckling as the game politely informed me that I couldn't move left. It's a good first impression. The game benefits from its goofy tone—set by the art, the music, the writing, and the sudden unexpected gun—and I wish the boss leaned into that goofiness too.
Especially since I didn't find the boss very mechanically satisfying. That might partly be because I don't play many action games, but the fact that you need to jump over and between projectiles with such imprecise controls (e.g. the non-variable jump) means it probably isn't just me. Maybe an action gamer could identify more issues, but...that's what I've got.
Also: The music stops and doesn't restart if you jump over the edge. This was extremely disappointing—on a repeat run and without the goofy music, the tone doesn't hold together quite as well.