The concept of using TS4 as an asset base for a game like this is quite interesting. I imagine it's cartoon style and low-end graphics makes it far easier to work with compared to 3D engines like DAZ (where a single render could take over 5-10 minutes to complete).
You basically have an in-built character creator that's so flexible you can make anything from beach bunnies to GILFs (as well as normal looking male characters, unlike Honey Select); on top of that, you can completely customize the locations and level design thanks to the build system, and there's tons of emotes, poses and animations to help give life to character interactions.
My only question to the dev, how do you find things like positioning and framing for screenshots? It's been a while since I played TS4, but I remember it being somewhat of a hassle keeping them in one spot for too long. Sims just have a life of their own, which is great for the game but not so much for when you want to control the scene