I can't really tell what it is, but I like your spanking games. It's hypnotizing to see cheeks spanked and wobbling. 😍
I have questions and suggestions:
Is this the newest Unity engine? I don't know. I have only experience with other game engines. I asked a friend and he said: It looks old or the game has no good lights. He said even "simple" models can look better with good lights.
Can you make a free camera? If you don't want to show the face, maybe make a limit around the butt 180 degree and turn the head little away.
Can you make the cheeks clickable? Like this it will feel more "in the game". Do you know what I mean?
Can you make the strength changeable while in spanking?
A scold dialog before and after would be nice. If her answers are not "good", the butt gets a second round. 😛
HL1998 suggested to add some cloth to strip down. I think you mean it's trickier because the underwear will look through. You can make puffy skirt or puffy pants that covers the panties. You can also "cheat". Hide the panties with pants on. On removing the pants you show the panties at the same time.
Your game is missing a spanking bench. 😁