CityEngine is one of many tools used to make Need For Speed. EA didn't use CityEngine as a start-to-finish solution. It sped up their development by reducing time spent on certain tasks so it could be reinvested elsewhere:
Game artists aren’t looking for a one-button procedural solution. Instead, they’re interested in procedural methods that help with ...
I have no idea about developing for Sony PSP. This answer presumes limited target hardware, and the goal of a simple 2D engine.
No, not money.
Your game will have a time budget and a memory bugdet.
The memory budget is how much it can have loaded at the same time. If you load a large tilemap, that consumes your memory budget. Similarly, if you load ...
AFAIK they achieve this by
Parameterized Procedural Placement
They create a workflow where you create a handful assets in this case building floors and they procedurally tweak the parameters such as Floor count,size,tint and custom props such as air conditioning outside of the buildings.
I once a saw a video about ubisoft creating a procedural assasins creed ...