The models and environments aren't rendered twice from two slightly different angels.What makes it pseudo 3D?
It replicates the one 2D image twice with each objects separated (between left/right image) according to depth.
The background, middleground and foreground are clearly separated but there is no proper volume however.
Pseudo 3D only requires 1-2% more from the system while proper 3D requires roughly 100% more.
Crysis 2 (console) and Socom 4 are two games which uses pseudo 3D. Killzone 3, MotorStorm 3 and Crysis 2 PC uses proper dual-rendered 3D.
Pseudo 3D = cardboard cutouts