The anime backs itself to a ero-game. Its remake made for ps4. So this makes me expect accordingly.
The story had held an amazing potential. They could have made the inception-interstellar of the animes but while making this show calling you back to watch more, left unsatisfied with irrelevant plotholes behind.
I can not say the music was bad, the execution of the story was awful and this looks like the animation team only focused on a more less perverted version of the game. The result is not bad but also not good. To be real; a good opportunity on a rich story with multi dimensions and time-space travels had been ruined... This is my humble opinion.