If we knew how to create world simulation, and how to make it working 4D, then humans would be able to plug themselves in, and experience 4D space. Alternatively there could simulated 4D beings, whose sentience could be transferred to robot body in our real 3D space.
What’s the game?
Itch io has several, I can’t find the name of the one I tried like 10 years ago. It was just a proof of concept, a freespace like fighter.
There’s also one that turns Minecraft into 4 dimensions, or it at least cribs the aesthetic of Minecraft. I forget which. It’s been a few years.