After watching this animation, I had very conflicting feelings about it. I was a bit disappointed because it didn't work, for me, as a sci-fi movie. But then I also realized that I wasn't happy about the choice of the races portrayed, as I think the Eldar Harlequines would make for a much more visually pleasing experience. Nevertheless, as a sci-fi movie, it might not have delivered anyway.
Then I had another, retrospective, look at what the movie presented, and realized that some essential aspects of the Warhammer 40.000 universe were touched upon in a balanced way. It doesn't distract the casual viewer, and it probably wets the palate of the die-hard Warhammer 40.000 nerd. (I am neither, I just happened to study this universe for a few weeks.)
The plot is vaguely interesting, though the action suffers from tempo issues at times, which I am sure any viewer will notice and be a bit frustrated about. The action sequences range from boring to fascinating. Here, too, I have some conflicting impressions.
The characters are clichéd but one is really not expected to care much about them in a personal way. They are all warriors, and in that sense, the Warhammer 40.000 universe's flavor comes through and it probably doesn't disturb too much.
All in all, I think I could have spent these 70 minutes in worse ways, and hope most viewers will gain at least the same amount of fun as I did.