This game's immediate failure to follow up on the events of the first game should've been a warning of things to come. The whole cast getting flushed for a new, weaker one, character arcs set up in the first game getting completely ignored (specifically Garrus), the main plot being a "villain of the week" filler storyline with no sense of urgency at all add up to a very weak sequel.

Fortunately the presence of Mordin and Legion, the gameplay improvements and the final mission being very ambitious and unique keep it from being a total waste of effort.