Feed test subjects to make their bellies grow. 

Once you've got a couple of coolers, a full tank of Specimen takes like, 8 minutes to process, and you can't be doing research during that time. I'm also not sure how it interacts with when you're actively "experimenting" on somebody.

That 8 minute gap in gameplay is kind of a bummer, and spoils the pacing. Just some way to upgrade the processing time would be great.

It would be pretty cool if there was an online multiplayer feature where you could play online with friends.

Different sliders for tongue length, width, height.

or DDLB, CDLG, CDLB and so on. Just a button that will make them call you mommy, daddy stuff like that.

Sometimes when the iris is light-colored, you cannot see the color or shade of it well against an outer white background of the eye. A thin iris-to-sclera border could solve it.

Military themed uniforms, decorations, things of that variety, to give the option for a military testing vibe?

It would be good to be able to control interactions using keyboard. Using mouse is disrupting the action. Or some other way to be able to simultaneously control the sexual activity and to give orders, comment on interactions etc.

Pubic hair and under arms hair

You know how in the original game you were a disembodied prescence that just acted as a pair of hands? Well I'd like to see that again. Added as an extra mode, your characted is a sexless, ageless specieless sombody in a sealed hazmat suit. You can only use your hands and whatever tools you have access to and nobody you experiment on reacts to you as if you were a specific person.

This is for people who would like a slightly more proffessional working enviroment, or just want to focus on the person in the rack without anyone else taking up the spotlight.