A dildo with a hollow tube through it, placed over the clitoris on a female (or male with a vagina). Can be sucked and that suction reaches the clit. Good for gender play.

You'd access this minigame when you've volunteered to be a subject. You're strapped in and blindfolded, and the screen goes black. Looking down in the direction of your own body, you may not be able to see it, but when you're touched by your handler in whatever way, that isolated part of your body glows. For example, if the handler runs their fingers down your side, you might see five glowing points moving in the darkness, following the contours of your body. Each touch or tool would need a unique touch-signature. While you're strapped in, you can make guesses through some interface as to what sort of things are happening to you.

Twists on this would be things like: a) Earplugs, yay or nay; b) different colors are associated with different sensations (blue for cold, orange for hot, red for pain or discomfort, white for pleasure, etc.); c) some kind of reward system, maybe tallying your right guesses at the end of your session and giving you some kind of perk or achievement; d) guesses can get gradually more specific (Something's happening to my vagina -> A dildo is being inserted -> It's an equine dildo -> It's GREEN) and more rewards are given for more specific answers.

Challenges: a) multiple things can be done at the same time; b) things only happen for a limited time; c) intense stimulation makes your character (and the UI) shake so it's hard to render guesses, but obviously not impossible; d) maybe parts of your body get 'desensitized' to a degree, and have a persistent glow that makes it hard to tell what's being done to that part; e) some toys have similar 'light profiles' so distinguishing them can be hard.

In interactions, you'd be able to apologize to subjects, as it is easy to make a mistake, such as miss-tapping "bite" rather than "suck," or accidentally overstimulating a subject. It'd be a quick way to ease a subjects anger, although apologizing would be a sign of weakness, therefore (dominant/switch) subjects would become more dominant.

Also, an interaction to ask a subject if you are going too fast/hard would be nice.

Would be nice to view the sex/masturbation at different angles and to see the action in different positions. Worm's eye view of a squatting position for example; where you can watch as pussy juice dribbles and splashes directly on the viewing camera(similar visuals with spent and shrinking cocks and filled holes).

Right now, masochism is not really a thing. There's an attraction to pain in the character creation but the character's response to it is always 'please don't do that, it hurts' or 'slow down, it's starting to hurt', even with submission and degradation. I'd really love it if they could actually enjoy pain or at least ask for it, but for now it's just not possible to have masochism. I think it's kind of a fundamental thing in bdsm, at least for me.

Your character in Rack is basically a shapeshifter, but this seems to be from a gameplay point of view. That is, something necessitated by the game mechanics. But what if you actually want your character TO be a shapeshifter. I think a mechanic where you could change forms out of the shower would be super cool. Maybe you could make some alternate forms in the shower, save them, and then become them at will. Suddenly switching from fully female, to futa in the middle of the room!

Herm's looking weird with alike human penis. Wanna animal-style it!

I had some ideas for alternate types or holding units for subjects, along with some concept art

Firstly is the gyroscope/ring type, that's realy common in sci-fi themed furry bondage pics

the idea is that the subject would be in a standing pose, giving you full acess to their whole body from the front and back at all times, the 0-G varient is just to be fancy

Next is kind of more of a joke suggestion, but some people might be into it

this floor bound/head down unit is based around having full access to your subject's ass and genitals in, as the name would suggest, a face down ass up position, like the song. i imagine it'd be favored for subjects with a submissive personality and farm animals

The third is the one i like the most and put the most thought into

this test-tube/vat model uses a one-way forcefield rather than glass, giving you full access to the subject, who is suspended free-floating in a breathable liquid with soporiphic qualities that puts them in a peaceful, docile state. i imagine that you wouldn't be able to directly touch the subject with your hands or fuck them, due to animation difference, but you'd still be able to use tools and toys on them, as well as terminals or devices that give any kind of direct access to the subjects nervous system

also the lights on all of them would be colorable with an interface for aesthetics, just cus it'd be kind of cool and sci-fi, you know?