Creatures Caves

First project and you choose Gaia of all things? I admire your enthusiasm. This is by no means a small thing. Sorry if I'm brash, but you might want to start a few house numbers smaller.

However, if you do want to pull through with this, there are several problems with the OG Gaia:

1. Gaia is a hybrid. Not quite creature, not quite agent. Being a creature with agent scripts tacked onto the side makes for a bit of a debugging nightmare. On top of the regular issues of working on large scale ecology handling agents, you now also have to deal with a moody little brat that might wanna do her own thing. Solutions exist, but it's still not something to brush over easily.
At the same time you will have to make sure that the genetics are in order. The best scripts in the world won't be able to rescue the situation if the genome is garbage. You're working on two fronts at once and only get a success if both of them are in working order simultaneously. That alone may cause a lot of frustration.

2. The default Gaia is a geat. It's a fourth creature species besides norn, grendel and ettin. Geats are annoying to work and play with because they can trigger arbitrary game crashes and the wasteland glitch. Maybe the steam version fixed it, but I seriously doubt that the publisher even knows of the glitch's existence, considering that there are no official geat breeds at all, and inofficial ones are scarce.

3. Gaia has an incomplete sprite set. That's not a problem per se, but still something to be wary of. Essentially, to keep the work load and file size comparatively small, many poses and facial expressions have been omitted from Gaia's sprite set. Gaia never takes on those poses and expressions, so it's not that big of a deal.
However, you might not quite have full control over her during the development cycle, so you could run into those invalid sprites during debugging. You will notice when the game spontaneously crashes.
A similar thing can happen to the end users. She comes with a warning to not breed or splice her with anything, yet people keep doing it. If you tell people not to press the big red button, they will instantly push it just to see what all the fuss is about. The emerging hybrids will not have the same limitations on their poses as mum, and the game inadvertently crashes.
Make sure to check out Gaius to see what a complete sprite set based on Gaia might look like.