Well, if the new interface/update wasn't buggy, you would probably hear more people talk about how nice it is.
Things I have encountered with the newest version on a brand new save:
Lust no longer seems to regenerate when you win surprise sex. You have to sleep to get it to regenerate.
Unable to overwrite save files.
Character stats don't update in the breeding pen. You have to exit the pen, then re-enter it to see current stats.
Along side that, you can no longer check the MCs stats unless you are in the breeding pen.
World levels are not being reported anywhere. Unless the Dev removed that feature (let's face it, he would never remove a grind like that), there are no indications of what is going on.
Most traits now say (WIP) grants XP, exceptions seem to be Busty, Buxom, and slender.
Harvested cum or milk seems to be worth 1 coin. Also, you no longer get x ml of fluid, you get a single item x fluid.
Monsters that are interested in surprise sexing you, won't stop following you.
You can have sex with a pregnant NPC ... AND get them pregnant Again, which resets their pregnancy counter.
My favorite is that you can be 'surprise sexed' while in the inventory system.
This bugged out my game and left me locked in a spontaneous blowjob with no way to cancel and no progression. I saved, exited, and restarted to find my MC at the farm with her dick stretched across the map to the catgirl that was still blowing her and I couldn't do anything until I interacted with her again.
The new UI does look prettier than the old one, but the old one worked. The new one is buggy crap, at the moment.
