All you need to do is double click the executable and it will launch.
Once you download it, that's pretty much it. In this case, the source is on Gamejolt - specifically, you can find it here. If that's the case here, then it's best to grab it directly from the source. Some of the software updates may slip through the cracks. While we do our best to keep everything updated, we are still human. First, you'll need to get an installation executable of the game. Five Nights in Anime 2 is a fangame that asks two questions: What happens if we take a horror game and take it straight into the opposite direction, and should we do it? The question to the latter is yes, of course.