I just wanted to post on here that the storyline is actually pretty strong in the single player campaign. Granted, you can burn through the both sides in just a few hours of playing, but that only talks about the present situation of the Ark.
The rest of the storyline is actually garnered from earning audiologs that you can listen and read in your dossier in the main menu. While this is not a game I would ever pay $40.00 for, the 6.24 (including DLC) that I paid is more than worth it. Hell, I bought Bastion for $15 and was done with it in 5 hours.
It's worth the price, especially catching the sale. Now if only we could get an update on the trainer.