Maybe I’m stupid, but I couldn’t figure out what I’m supposed to do even after playing many times. The game doesn’t seem to give you any indication whether you’re doing things correctly, even after you finish it.
Ah, I will admit the evaluation turned out to be a bit random. And we didn't have time to add dramatic effects reacting to how well/bad you are proceeding. So as it is, I'd say it's just about having fun with it and trying to get all of the lil demons!