The idea sounds fun. But there is a lot of "buts".
Controls: Why not just make LMB spell 1 and RMB spell 2, I was all the time making this mistake, as it feels so intuitive that way.
Movement: The player has too little friction, so it feels like walking on ice. There is almost no control when in the air, which makes any kind of precise jumping nearly impossible.
Spells: It is a really interesting idea, but at the moment I don't even see the difference between scaling up and scaling down (except when doing it to a platform). I was thinking there will be different kinds of enemies, ones that are easier to scale up, easier to scale down. Also making it so you could jump on the enemies would add a lot of depth. For example: you could scale an enemy up to jump on it and use it as a platform. And the bigger it is, the higher you bounce on it.
Level: I came to the moment where you are high and there are two enemies, I didn't know what to do from there. Is it the end? I tried a couple of directions, but because the controls are so annoying, and when you die, you start from the beginning, I just gave up.