I'm sorry, but I couldn't get passed level 3. The idea is good, but wasn't executed properly. My first gamejam game was neigh unplayable, so I know the feeling.
So advice that could make this game better (without changing it): Adding coins with a coin counter: (Coins: 1); Adding an objective marker (A star-like object that rotates rather than a blue wall); more responsive controls (adding a double jump rather than jumping unintentionally when landing); a text tutorial on the wall, making the cubes slower (rather than just ramming you) and thicker platforms.
I find that constructive criticism is better than telling someone their game is bad, or just blatantly lying and tell them it's good enough to be released on Steam. So good attempt, and hope this helps. If you'd like some inspiration, I went from looking like this game and 4 gamejams later, I make this https://literally3d.itch.io/taking-the-w.