LA Hallucination: Side B, is an expansion that adds more trials based on songs from E•MO•TION: Side B and a new ending. The new trials are messier and more self-indulgent than those in the base game and are less focused on the setting of LA. It's more focused on developing the hallucination as a setting/character while still keeping the relationship between player characters as the main focus. If that sounds interesting to you, that's great! There are instructions for how to use the expansion in the PDF. If it doesn't sound interesting to you, you can ignore it and just play the base game. Either way I hope you enjoy your time with the hallucination. Source: The Developer Website.