As an X-Com and Silent Storm fan, I have a low tolerance for this type of genre when they don't have quality game play and interface. The 3D graphics and tactical combat is exceptional, although I think I actually enjoy the strategic management (research, weapon and character development) the most.
Afterlight also has a great story line which seems to be fairly flexible. The overall balance of the game play is highly addictive. "I'll stop playing after I research this next tech..., after I build the new base structure..., now I can upgrade my guns..., oh another tech..."