subwaysurfers based level instantiate.

In Subwaysurfer they actually seem to have predefined sections which they simply put together in a random order. Placing seperate objects distributed in 2 directions is very hard to do since you have to do a lot of checks if there is actually a runable way through your objects. If there's a dead end you have to replace one element with a ramp or delete it.

I play a lot Subwaysurfer ;) and it's definitely predefine sections. The predefined sections have to be designed in a way they can be put on every other section. An alternative would be so each section type has a list of possible successors.

Predefined sections also have the advantage that they represent a single drawcall since all geometry is in one mesh. To me it feels like each section has some hardcoded and some additional moving-train spawn points.