I managed to finish the game in about four hours, though I don't know if I unlocked everything; there doesn't appear to be a gallery, or at least not one that's not hidden behind something extra. I thought it was a fairly easy game until the final boss, which took a couple of tries (mainly because it can heal, fly far away, and loves to spam attacks that make you orgasm and waste time - talk about frustrating). It doesn't look like the NPCs have animations beyond whatever enemy is raping them at the end of their respective levels (I've even poked around in the assets a bit in an attempt to confirm this and haven't found anything that shows otherwise), though everyone is compatible with the restraint stand/buttock wall traps and all enemies that have animations in conjunction with them (naturally, however, you only see their rear ends, so not much variety beyond different voices/socks).
There is a diamond material to unlock if you defeat all of the bosses again in the final level (which I gave up on due to getting lost too easily when trying to find where they're all hiding) and defeating the final boss a second time, when they're further powered up. I'm not sure what it's used for, and don't really have the motivation to unlock them right now. If anyone wants my sorta-but-not-really-completed save that has the final boss defeated once, here it is; it goes in your user folder/AppData/LocalLow/azcat.