Some of my friends also complained about that, but really the stun hitbox is as big as the sprite, but maybe the sprite is one pixel off. I hope it wasn't that frustrating!
I think what threw me off was that the player's hitbox covered the entire sprite instead of just the bottom half. So I kept running into stuff with my head :D
That's really interesting I never thought of making the hitbox only cover the lower part of the player, that would solve a lot of problems now that think about it! By the way, your game was really enjoyable and quite challenging!