Decent attempt at something different, but needs more polish and a pause button.
It is a good system and it has the potential for a lot of depth. It also offers a fair bit of flexibility in how you approach different situations and it includes a reasonably well done RPG experience system.
Sadly, while playing the game can be great when everything comes together, there are some small and big issues that really detract from the experience.
The most notable of these is the sheer amount of chaos that goes into most battles. Sure, you can plan most of your actions, but once the fight breaks out, things get very hectic very fast, and frantic clicking soon gets the upper hand over precise tactics.This is worsened by the fact that units respond sluggishly and sometimes wander off by their own. On normal difficulty this is workable (it does take the tactics out of it a bit) but on higher levels, one wrong decision can easily get you slaughtered, meaning you have to restart the entire mission from scratch (that's right, no in-mission save!). IMHO that only adds frustration, not challenge.
For the rest, the game is servicable but nothing special. The graphics, the music, the interface design, the story and the characters..it's reasonably well done but it doesn't stand out in any way. If you compare this to something like Starcraft II (which is apparently based on Warhammer 40.000) the difference in production values is staggering.
So, is this game fun? I'd say yes, but only in short burst; on normal difficulty, the game is forgiving enough not to let the lack of precise control become a real issues..but it's not all that tactical and becomes repetitve fairly soon. On harder difficulties, the lack of a pause button combined with the unforgiving save system soon causes more frustation than fun.