1.-A scene of drama, without dramatic music is just a poorly made comedy
2.-Manipulates the viewer's feelings
3.-It makes everything look nice
4.-You get addicted to the game
5.-Each time you hear a track you feel familiar with the game
By far my favorite Original Soundtrack is of Kokoro Function, did you ever seriously thought about an OST that manipulates your mind?
PD: Imagine this with a sad music





