Are there really different endings? The game was pretty linear other than the dialog choice right at the end.
Victor's favourite memory stays the same either way, just the flavour text before the credits changes depending on what you did to the characters you could either kill or spare, which is just the Dr., Jonathan and Mabel.
Couldn't figure out how to save Mabel.
Here's the save file for the orgy, if you just want to see what the game has to offer in that regard. The path is AppData\LocalLow\Movie Games Lunarium\Lust From Beyond\profile.
I think this is the longest sex scene and probably the only one that's more erotic than violent. Beware that the male player character gets raped by another man atleast twice. The best scene is the one at the end with Mutant Amanda imo, but it's more creepy than sexy.
Other than that there aren't that many scenes. I was really hoping for more voyeuristic stuff, where you could come across the members of the cult just going at it in different parts of the mansion. like in the prologue the scene with Mabel and the two headed guys.