Without a doubt, this is one of the funniest games I've played so far haha. The humor fits incredibly well within the game's overall concept, which makes it work amazingly well without ever feeling forced or unnatural.
I have to say, the visuals are wonderful. I really liked your pixel art style. The environment feels very lively thanks to all the different elements present throughout the scenes. The animations are smooth, and everything comes together really nicely. If I'm not mistaken, the perspective you used for the environments is called isometric, right? It's a style I'd love to explore myself someday, and when that day comes, I'll definitely remember your game as a source of inspiration.
The music and sound effects matched the game's atmosphere very well, although I did feel that the attacks could have a bit more impact with some additional sound effects and subtle screen shake.
The gameplay is simple and straightforward, so I didn't run into any issues there (except for the fact that, since it's a browser game, Ctrl + W ended up closing it a few times, but I know you're already aware of that haha). I also think it could be interesting to include a small tutorial during combat, just to further reinforce how the player should proceed.
And finally, one thing I thought was absolutely fantastic was the fact that each hero has their own unique role and way of attacking the boss. It added so much life to the game and really made us feel like the final boss of that world (even if we don't have enough mana to do absolutely anything).
Congratulations on the project, and I wish you the best of luck in the jam!