/3/ - 3DCG

Is there a clever way to "flatten" a 3d render? I've had some success using completely solid lighting domes and some fancy postwork filters, but I was wondering if there was a way to render it differently to aid the process? I appreciate it's odd asking for way to make a 3D render "less 3D" but any help with this would be appreciated.

For example: BlazBlue appears to be using 3D models for the characters and animations, yet they look pretty much entirely 2D. How did they do this?