Not my finalize review as I only played the Mary Skelter nightmare (the first of the series) in the ps vita. What I found in the description is that this Mary Skelter 2 contains a DLC where it includes Mary Skelter within. So it's a 2 in 1 game.

The gameplay is a dungeon crawling game where the character is somewhat like a vampire which reacts to blood. The blood feature is a distinct feature for mary skelter as it will affect your gameplay. Though I could not say much, this game has good music and graphic.

On a side note, mary skelter 3 (Finale) is going to release. But unlike this game where it has the previous game, Mary Skelter Finale only provide cut scene within previous game with no gameplay available. So either you buy this game to experience first-hand, or wait for finale and slowly watch through all the cut-scene.