Even if it was all supported in the software,your center of focus would be right in the bezels or offcenter(through software that becomes a whole other problem).
Think about playing a FPS with the cross hairs between the monitors..or a driving game.
But yes,you can game on them but you'll be restricted to the highest supported common resolution. i.e if one only supports 800x600,both will have to run at 800x600.