Pretty good little platformer. The arts were nice, the boss was pretty good too, I like that the clothes dissappeared half-way through, heh. The platforming was challenging but not too annoying, you striked a good balance
Like others said, I'd remove the spacebar jump and maybe add some text that tells you to use the mouse to jump. Would be cool if pogo-jumps kept you bouncing on the same height forever.. or maybe allowed you to speed up more (like bunnyhops x3)
There are a few 'blind' jumps, ones where you don't know where you will be landing because its off-screen. Dunno if its a screen resolution thing but yeah, that can probably be fixed by moving the camera to the right rather than centering it on the player
Either way, good job! You drew a lot of arts, that's impressive