Complete level 4 making Midnight's friend smile.
This one might be a tiny bit tricky. This is the hardest trophy in the game which says a lot about the difficulty level of this list. To make him smile you need to bump into him, but you also need to complete the level. If you take too long he will block the way and you won’t be able to complete the level. You might need a few attempts to get the timing right. When the friend is close to falling down, fling yourself over so that he will hit off you as you fall into the completion zone. There is a video guide in the walkthrough that will show you how to do this, but honestly, you will likely get this without even trying. It is very easy to do and highly likely you get it without even noticing.