So i got the chance to play around with this yesterday and there were a few things that jumped out at me.
1.) I think it'd be a good idea to have players start off with a tutorial. I know you can access the tutorial through the menu, but the fact that it doesn't pop up automatically may be a problem for some people. It took me less than 3 mins to figure it out, but I suspect that won't be the case for a lot of others.
2.) Once I figured out how to play,it ran pretty smooth for me. I think I only came across one bug and it was after the breeding segment. My cowgirl never loaded in after the orgasm so I had to load a previous save to get her back. Not really sure what happened there. I tried to recreate it but it didn't happen again.
Since it's just a test build, there isn't much to explore, but what's present is pretty good. I've been keeping an eye on this thread for a while so I'm happy to see a playable build! I'll continue to keep watch to see where it goes.