The game is that easy. Boringly so, since all the massages are basically the same set of spots. Once you click a blue spot, you have to press the arrow keys until it's over. At first it's annoying because you have to constantly reapply oil, and you have no instructions that you should "clear" each part before moving onto a new one.
What I did was focus on the energy upgrades first (lightning) because that allows you to clear more massage spots, and you get 5 coins for every fully massaged area. That makes it easier to get the Oil upgrades to reduce the number of interruptions. Finally the book upgrades unlock the following stages.
So the game is not that hard. But it's really not worth it. You always massage all the fairies in the exact same way, and they lay in your hand in the exact same way. The only difference between them seems to be their clothing/face and the final scene. Which is also rather boring because they interact with all tools/body parts in a very similar way: Either licking it or bending over, with minor differences for each character.
