Factorio on a Pentium pro sounds very tricky to do effectively. Half Life still is great but the graphics in HL2 make it more immersive. That's slowed but I wouldn't cite 98 for that.
On a resource constrained system, you'd be limited in how big and complex the world can be.
Now imagine factorio, but in multiplayer the world calculations are divided amongst clients so you get a bigger and more complex world when you have more players.
