The answer is a yes and no mix to can you get into trouble.
If you make a game and aren't selling it and the photos are posted publicly and you make some sort of change to them you could argue that it falls under fair use.
If they aren't publicly avail, flat out yea you are asking to be sued.
What you should do is talk to a copyright attorney because that's what we are talking about.
Also if the girl resides in the EU vs the US you could be asking for trouble even if they are posted publicly and you aren't making a profit.
As for making a profit different courts will look at stuff like patreon differently some don't see it as selling a product while some see as the same thing.
While rk-47 suggested using pornstars they are also protected under the same laws. That said you might actually find some of them willing to agree to help simply for the added publicity.