A toy.
Definitely just a toy for now, it's like playing around in a cumflate-y Gmod.
You grow kobolds from eggs; when they're adults, you can slap them together like a couple ragdolls to make them have "sex" and harvest them for their... generic heart item (or now eggs, too) that you can sell so you can afford more eggs or more flasks to fill with various potions you can make to TF the kobolds bustier or taller or whatever.
That's basically all you do so far, sexing kobolds with each other, grinding stuff into liquid, mixing odd TF potions, buying a couple basic upgrades, and Quake bunnyhopping around the map.
TBH, I can't decide between giving this a 3-star rating for being a simple sandbox toy, or a 4-star rating for having a lot of promise and being fairly enjoyable as-is.
I'll give it a 3-star rating for now, with the promise that I'll update my review when the game gets some more content.
TL;DR: I definitely recommend playing with it, but it's definitely 100% a toy for now, not for any serious, lengthy playtimes.
EDIT: development is going pretty smoothly. It's still solidly a TOY, but among the newest updates, there's the ability to make ice cream, used for making kobolds gain bellies/weight permanently.
EDIT2: after a couple years of dodgy updates that make the game less fun (I'm still a bit salty about them replacing the old bunnyhopping with the "real" kind), I really can't recommend this game outside of just downloading it to fool around with it for a bit once. I think what would save the game is if the open source aspect of it was utilized and the game got a modding community, but most of the time I feel like the game's time has passed, it's just not pulling the numbers it used to, and everyone that talks about the game just reminisces about how it used to be more fun. I'm dropping the score to two stars, I'm just not enjoying the game at all anymore.