Good start! Cute weird sprite. Overall I thought the visuals were nice. I agree with PolyB that it feels a little slippery. 

A solid beginning that has good fundamentals.

PROS:

• Did have a powerup that was necessary for completion of the game.
• Simple in nature, but didn't have any real bugs that I could tell.
• Inputs were very responsive for some tight jumping challenges.

CRITIQUE:

• The inputs actually felt a little too responsive since I'd just tap the movement button and often move far enough that I'd pass completely over a platform that I needed to stand on to make the next jump. Maybe either reducing the movement applied each frame from input or slightly increasing drag on the character would help prevent overshooting so easily.
• Adding some form of hazard to the experience would help increase the player's engagement. It doesn't need to be something as complicated as AI or something as punishing as a death pit, but just something as simple as a pinball bouncer that boops you in a direction that you don't want to fall would give you some more room to play with level design.
• It's ok to have a limited scope game to try and focus on really learning specific things, but it would be nice if the game was less linear than "go left to get powerup, then right to win". Adding some more verticality to the level design to limit the pathing of the player to only go towards the powerup while also showing jumps that they really want to make (and will be able to make once they acquire that powerup) would look more interesting and feel less linear.

Graphics are good

Cool player movement but sadly an unfinished one