Nice job! I appreciate the work you two put into this. More in-depth review incoming:
Design [3/5]: A lot of other people have commented on how the controls feel imprecise, so I guess I'll start this by throwing in my own two cents on the matter. Yes, the controls are imprecise. Yes, the physics are a little chaotic. Sure, it's difficult to control your character. The thing is, I don't think any of those are weaknesses all by themselves. Character movement and physics don't exist in a vacuum: they exist in a game. A game which has levels, puzzles, and decisions to make. My point here is that having an imprecise character can actually be a positive thing if the rest of the game's design facilitates that. For example, I Am Bread is a game where you play as an awkward physics object that is terribly difficult to control. However, it's still fun to play because of the unique level design, aesthetic, and hilarious narrative. Having said all of that, my main criticism of your design is not that the controls are imprecise, but rather that the levels and the objective of the game didn't really feel like they were designed to work with the way you control your character. I think this game's biggest strength is being able to throw your character around like a ragdoll using the platform, but I don't think the rest of the design capitalized on that strength.
To explain this point in a little more detail, I think one of the most questionable design choices was to make this game an autoscroller. For me, the most fun part of this game was flinging your character into the pink mush at the end of the level, basically treating the platform like a catapult. That was genuinely fun, but I wish there had been more moments like that intermingled throughout the levels. The fact that it's an autoscroller means it's usually far safer to just keep the player on the platform at all times until you reach the end of the level, slowly avoiding the enemies and inching towards the collectibles. I think it would have been far more fun if you had more freedom to toss the player around, having a camera follow the action until you reach the end of the level.
There's some more missed potential in the obstacle design. The enemies have an interesting property: the player dies if they touch one, but the platform can just move right through them. One idea that popped into my head as soon as I started playing was "ooh, it would be cool if there was an obstacle that the player can go through, but the platform can't". Such an obstacle type would require you to toss the player through it and then find another path for the platform to take while you find a way to catch the player. I'm not criticizing you for not including that idea specifically, but I do wish there were more obstacle types than simply moving killzones for the player. Again, I think you might have had more range in that respect if this game wasn't an autoscroller.
Considering the dissonance between the controls and the level design, I can't give this a full rating in the design category. Having said that, I think the controls are fun. As I mentioned above, it's really fun to toss your player around like a ragdoll. I just wish the game was mostly about that rather than slowly and precisely avoiding static obstacles. The controls are imprecise, but the level design often requires you to be precise, which just slows down the action and subtracts from the fun of chaotically tossing the player around the screen.
Adherence to the Theme [5/5]: I can see the argument that this is a platformer with only one platform. However, it doesn't exactly feel like a platformer to me. This feels more like a physics game to me. But I understand that's a pretty subjective point, so full credit from me for adherence to the theme.
Originality [4/5]: There aren't too many physics-based games where you can't actually control the physics object directly, so that's pretty cool. The only other example I can think of is Rocket League, since you don't actually control the physics-controlled ball directly, but this game is something totally different. The enemies, however, feel a little uninspired and didn't stand out to me, and collecting objects didn't feel terribly unique either.
Overall, good job! Keep doing what you're doing.