There is a lot to love about this game, but I agree with some of the comments that it could feel hard to know what to do next or how to progress. Also, the goo felt too unforgiving, so maybe having it shrink when coold could add a bit more strategy and leeway.
I also found that because the direction of the spell got locked before you could draw, I would find myself firing in random directions quite often, which felt a bit frutrating