At first, I was not sure of the cause of the fires. Once I managed to avoid them starting, my 'happiness' rating stayed at 100 very easily, and i quickly filled the whole screen, so that no more blocks could be added. A better balanced difficulty arc, with an easy start, and building difficulty, would make this more fun. A defined goal would also be nice (I thought there may be a win state upon reaching the top of the screen with no fires, for example). I liked the consistent, charming visual style and sfx, but some music would have been great. The comments and tips at the bottom are a nice touch.