There's humiliation and public sex with Gunnar and Rhot but more so with Gunnar.
To add to the watersports comment, there's an instance of pissplay though from a side character only. No spitplay... yet. (though I hope we get one with Gunnar someday)
There's some group play/gangbang with the bandits and the lizard tribe.
There's also some threesome/spitroasting scenes.
Wouldn't know if knotting is considered a kink/fetish but there's that too.
Obviously there's a lot of dominance and submission aspects already from the majority of our enemies and allies.
Can't remember if there's a feet worship scene yet, but I hope we get one. There's some armpit sniffing scene with Logan though but it's a one time event only I think.
There's a lot of voyeurism scenes for player characters with Bottom Logan route too.
There's also a bit of bondage scenes, I think.
No cuckolding as far as I'm aware. (yet) But maybe we could get that with Bernard and Gunnar. Think Gunnar would like that idea based on his scenes about almost being caught fucking the player by Bernard a bunch of times already.
No ageplay, fisting, orgasm control/edging, impact play, cbt, and breathplay yet as far as I'm aware.
Also for a game with lots of muscle bara characters, I have yet to encounter a muscle worship scene (like licking muscles, licking pits or sucking or caressing them pecs, kissing biceps, etc) There's a short one with Gunnar but... it didn't feel muscle worship-ey, more like just a simple massage.
There's actually muscle worship now that I remember, with Korg and Ste.
Maybe I'm forgetting somethings too but these are all what I could find. Everything else is the "normal" sex scenes with all the characters and by "normal", I meant more like sub/dom undertones sex. The most vanilla one I could find is with Bernard scenes.