Well done. Art, despite being basic, serve it's purpose. Gameplay is working, each level is unique and simple in it's core. I misunderstood controls first and expected it to hold shift to absorb and then press to release, not sure why. And first levels can be completed without holding it inside at all. Also not enough time for mee to read text. But for the first jam it is pretty solid anyway.
Also maybe you shouldn't focus on doing everything from scratch. After all you using whole engine anyway. Making a good game is more important. And if some assets for background or simple logic was borrowed (legally of course) and saved you time for better game design or story why not use then? It is bed only if main "selling point" of your game is borrowed. IMHO of course.