It would be cool to find an engine proposing full Blender plugin.
by full i mean : import diffuse map , specular map, normal map,
glow map , and lightmap for levels also.

But irecognize S2 engine , is already complete working next gen !
with normal, specular , dynamic lights , soft shadows and all the rest,
all reday to use

A7 have some lot of work to reach that state of integration
(shaders, lights, shadows) and workflow.