Mass Effect 2 is fun to play.
If I had any major complaints-it’s no Samara romance, the loyalty missions get stale once you’ve done them a dozen times, and the suicide mission becomes easy to game once you know how to do everything right. Thus losing its punch when you are playing the first time.
(Though if your trying to get certain outcomes in ME3 you have to game it right).
Excellent soundtrack, though the combat lacks the Hollywood action style of the third game and the forward focused aggressiveness of the first game. (I actually like in ME1 charging into pirate bases and feeling like I’m a spec ops badass).
Within the overall story of Mass Effect-ME2 develops the two subplots of the genophage and the quarian Geth conflict, and sets up their resolutions in the third game. The reapers however become more of a problem-with the collectors as simply reaper proxies(that are themselves actually not fought that often), people have different feelings on how it treats the reaper’s motivations, I personally think it’s fine. I can understand why people think otherwise though.
I don’t think ME2 is a diversion per se, or that it is unnecessary. I do think the problem ME3 had was finishing the main plot and the two major subplots(along with wrapping up the characters of the virmire survivor, any romance options, and tertiary stuff like the rachni) with all of ME2 characters both one-shafted to more minor roles, and two having to ensure they were included.
As someone who has played the ME trilogy probably three dozen times(I know nerd) I think a lot of the criticism the games receive is somewhat unfair. The story is actually fairly consistent and generally explanations are given. Even for things that are a bit cringe like Cerberus’ role in ME3-an explanation as to why is made.
As for ME2 though-beyond my earlier complaints, it also lacks the crew interaction that ME3 and definitely andromeda has. Everyone pretty much just sits in their room. Which sure yeah it’s a bunch of professionals many with death wishes of some sort-so not a lot of camaraderie but it does get more noticeable.
