Also, my sis bought me Ultramarines the movie for xmas so I thought I'd share my thoughts on it (also, SPOILERS):
It was pretty forgetable really, but at least it wasn't awful. The acting, while not exactly oscar worthy was perfectly adequate and there were only a couple of points in the script that made me wince slightly. However, apart from a couple of scenes the film didn't really do anything for me until the marines had actually got off the planet in the last 10-15 minutes of the film.
The battle with the demon was actually quite exciting and the confrontation between the surviving Fists/Ultramarines was ok. I feel that if they'd spent a lot more time on the ship with someone being a traitor and killing off the other survivors and the marines and audience havint to work out who it would have been a lot more interesting.
The "action" on the planet was overlong and boring. They were clearly trying to get around their limited animation budget by setting it on a barren planet with a very dusty/foggy atmosphere but the lack of visibility didn't create any tension, it just made it look like a test animation for the marines themselves set on a flat plane.
When they finally met the enemy they weren't exactly inspiring from the POV of a 1st timer or a 40K fan.
Putting myself in the mindset of someone new to the series the buildup of the enemy felt like it should have been something really wierd and alien or truly horrible, the way they come across their landspeeder hovering in place with no response from the crew was actually quite good, but when it comes its like "oh...so it's their evil twins...they wear black armour and have faces like Freddy Kreuger...consider me underwhelmed".
As a long time follower of 40K the chaos marines, Black Legion no less, weren't a cunning an ancient evil that have been fighting for 10,000 years, they were a bunch of mooks getting mown down by the dozen.
Whether a newbie or a longtime fan they just didn't feel like a threat, just faceless goons to privide the heroes something to mow down. If they had had some cultist to fill that role and had maybe a single squad of Black Legion as enemy characters with a bit more to them (everyone loves a good villain), a real conflict of equals, then the first 3/4 of the film may have felt like something memorable instead of a bunch of guys in blue armour walking through fog and blasting a few chumps in black armour.
The animation wasn't great, especially the backgrounds as mentioned before were either just fog or rendered out of focus as if it were a camera shot and at some points in the film you got the impression you were watching a computer game cutscene from a couple of years ago, not an animated movie. The walking animations were particularly noticeable as being somehow 'off'.
Still, it didn't stink, that's the main thing. It was kinda bland but it wasn't an embarrassment and thats more than I was expecting. Apparently the company put up the cash for the film otself, no funding from GW. With a budget of 9 Million pounds I can see why the animation wasn't so great but they still could have done a better job of the actual story.