Blender 3D has a per scene anaglyph game redering mode.
for those of you unfamiliar with this, anaglyph means the additions of blue and or red pixels highlighting the edges of a 3d object for use with red and blue lensed 3D glasses, with the addition of game textures such as Open GL/per pixel maps the red and blue highlights are then calculated on a per pixel basis.
this was one reason I really suggested blender as the main GE for the plan Z projects, blender can do anything, it's just a matter of figuring out how to do it, most of the time it's as simple as pressing a few buttons
heck, I'm speaking about blender 2.49b, not sure what 2.6 can do (I've only messed with 2.6+ a few times)
anyways, I saw this thread and I initially thought it was about something else entirely which I will now rant about;
(my sarcasm = other peoples real thoughts) OMG 3D!! like it's instantly totally more cool and better than it's 2D predecessors even if the story, artwork and gameplay sux in comparison..
rant over.