I think EA are waiting to see how word of mouth affects the sale of Dead Space Extraction. I believe the original Dead Space had quite a long tail thanks to word of mouth from reviewers and players alike, so that it eventually reached really good sales, even if it was blown away by first month sales in comparison to a similar game like RE5.
I enjoyed Extraction as someone who had played Dead Space. In fact, I think I enjoyed Extraction more than the origianl game, but that may be down to it being a co-op experience vs playing the main game by myself. The guy I played it with hadn't played Dead Space and he enjoyed it too, I don't think that from just playing Extraction, there's any way to tell it's a spin off. It's treated as a full story and it feels like the main story in a very fleshed out, if a little cliched, world.
I don't want people to downplay the quality of the game, it's good. it's very good. It lacks replay value, well that's a matter of opinion. It has harder difficulties and challenge modes, there were a couple of times when you chose a different route (although I understand this doesn't make a huge difference to how you navigate the level) in the campaign and it had above average production value on it's voice work and story elements that allow me to play it a second time without being too anoyed about now being able to skip cutscenes. As a straight through one time co-op experience, I think it was worth the £32 I spent on the game. I don't think I'd say the same if I were to only play it solo.
But heck, I only paid £8 for Dead Spce on 360 (brand new from Asda) so buying this at nearly full price is probably just karma evening things out.
