Great little demo! Especially for your first attempt at making something, I think it's great that you kept it simple and you're able to deliver an interesting challenge nonetheless.
I couldn't get past the third level - looks like the energy drains at an uncontrollable rate? I don't know if it's a bug or not.
Otherwise I think the gameplay is super solid and what would be amazing to add to the experience is a ton of Juice. Do you know what Juice is? If not, we have a whole video about it on the MakeGamesJLM Youtube channel:
Start adding layers and layers of juice and this could be a masterpiece.Keep it up!