Great game with short lfiespan.
It would've been nice if they added more. The main storyline was good enough except it wasn't continued with the expansions... why.... /shrug.
The game also seemed to be much faster paced then other strategy games. I really liked how you can zoom in to get a first hand view at ground level of whats going on in battles and where troops are. You also cannot cheat in the single player campaign. I found the AI lacking, as it tends to just rush you instantly upon creating units. It also cheats, where even if you destroyed enemy HQ's it randomly spawns units to constantly try and deplete your units.
I found the most useful strategy was to build defensively around the main base, emplace numerous turrets, then create a number of whirlwind artillery tanks, and with scouts, simply pound enemy units from afar. The enemy AI was such that it just stood there taking the artillery...
I haven't tried mutiplayer yet, doubt I will.
While there might not be enough single player missions you can "skirmish" and pick maps and fight the computer in set battles. Theres a huge number of maps available and the expansion "Winter Assault" adds another army, the Imperial Guard to the existing, Eldar, Space Marines, Chaos Marines, and Orks.
While nothing innovative, this game was interesting to follow through but having beat the single player campaign I don't have much interest in continuing to play.