Well-cum. You want to avoid anything with the red "VN" prefix or anything with the purple "Ren'Py" prefix. For everything else, you have to see what interests you and look at the tags, previews pics, read the descriptions, etc. The site does not make it easy to avoid VNs and the like, though that is what makes the bulk of the games here.
I can give you a few recommendations to start with, although be aware that many non-VN's have huge filesizes and tend to run like crap. Almost none of them are complete, either.
- Breeders of the Nephelym - This one runs ok and isn't that huge.
- Wild Life - This one's huge and might run poorly, and it's mainly for checking out animations. But the anims are fantastic.
- Hunt and Snare - Furries. Furries everywhere. But you can shoot stuff with a rifle so that's cool.
- Carnal Instinct - More furries, but there's human PCs also. Another big file size and great graphics, good animations.
That's a few to start with. There's other player-controlled games out there that aren't giant sandboxes like these ones, but I'm sure you can find them.