On the one hand, no survival horror title I've played, either on PSOne or PS2, has had a more effortless, natural-feeling control scheme. You're given 3D controls that make use of the Dual Shock 2's analog sticks and you run the in direction you point with the left stick. On the up-side, there is a fair amount of challenge and strategy to the game. It's tempting to use ammo on all those slugs you encounter in the early going, but gun ammo is rare and would best be conserved for boss encounters. On the other hand, if you resort to knifing the slugs, there's a chance you'll get pounced on and infected.
Conserving resources plays a BIG role in the game.
My only complaint is the Save Game scheme. This is the biggest flaw in the design of Extermination. At least the game is deep. I'm about 10 hours in and still going strong. Considering Konami's Z.O.E. and Shadow of Destiny can both be beaten in a fraction of that time, Extermination is a fairly meaty PS2 outing.