An average piece of expansion... saved by it's incredible and heart-rending ending
Breaking down into approximately 4 on foot sections and a vehicle one there's plenty of variety amongst the familiar; and a memorable battle on a satellite dish a la Golden eye aside it's all fairly standard procedure.
However in the final installment which sees you attempting to disconnect a rogue VI that has killed the all the researchers bar one Shepard becomes infected with the virus, entering him into a matrix-like environment that allows him to share the memories of David, the noble scientist who attempted to join with a virtual intelligence computer program.
Aside from turning everything you thought you knew about the mission on its head the final section manages to be heart-rending and horrific in turns. An amazing feat for any videogame, let alone a 2 hour add on.
There is absolutely nothing wrong with opening section of this game, it does everything you'd expect from Mass Effect, it just didn't do anything surprising or spectacular, and without the finale it would have received a much lower score but.... damn it.... the Atlas station mission makes it all worthwhile, even if I'll now need brain bleach to remove that last haunting image.