Some of you are (ok, most of you ) seem to have issues with the more technical aspects of the game ie. looting, weapons systems, and so on. I didn't mind any of that. In fact, it was far preferable and far more manageable than the over system in ME1.
However, the game, while amazing, is not perfect. The majority of the game is spent recruiting members of the team. Now don't get me wrong, I really enjoyed the recruiting missions, but the problem was, this took up the bulk of the game. The recruiting itself is not really part of the core storyline. If you strip away the recruiting and the loyalty missions, you have once hell of a reduced game. What am I getting at? This: the game needs more main-quest plot mission. If memory serves, the only missions you have to complete outside of recruitment are: the prologue, Sherphard's awakening, Freedom's Progress, Horizon, the IFF mission, the suicide mission. Not a whole lot when you strip it down like that.
On the other hand, with ME1, you had to do Eden Prime, the Citadel, Therum, Feros, Novaria, Virmire, Ilos and the final Citadel mission - they don't look like much on paper here, but actually those missions generally took longer, and you had to do them as part of the core quest.
I may be contradicting myself a little here: I love that we have the choice of recruiting who and how many, but realistically, won't everyone just recruit everyone? Why would you leave someone out? This is great as character development and interaction, but I couldn't help feel a little jipped in the overall story progression of the game in terms of the main quest.
Another complaint: there was no "big decision" moment when you have to make a decision there is no coming back from. In ME1 of course, you had to choose between sacrificing Kaiden or Ashley, in ME2, there was no such dilemma. I think they missed out with this. The biggest decision in the game ultimately was whether or not to destroy the Collector base, but even this felt somewhat lacking compared to choosing between saving the Council or letting humanity take over. I think what ME1 so great for me was it was all about the hard choices - I didn't find myself having to make any really tough decisions in ME2 - the one I wrestled with most was whether or not to hack the Geth (I did) and also who to take sides with between Miranda and Jack (I chose Jack), but even here I was able to get Miranda's loyalty back.
Of course, these are minor quibbles about an otherwise great game: excellent characters, much-improved class system (like, MUCH better), great locations, much better inventory and battle system, the only thing lacking for me was the storyline. I needed more surprising punch-in-the-stomach moments - something genuinely shocking that changes how you look at things. The closest ME2 comes to this was revealing the Collectors used to be the Protheans - but that's it. I needed...more. I spent half the game convinced the Illusive Man (notice ILLUSIVE, not ELUSIVE) was actually not a man at all, but some kind of Geth program plotting to totally screw over humanity (which would have been freaking mind-blowing and worthy of the "Empire Strikes Back" tag that's been attached to the game)...but no, he apparently really is just a man.
Another minor quibble: I miss the Citadel, and strangely enough, the Council. Sure, running with Cerberus was cool for a while, but I hope Shephard returns to being first and foremost a Spectre in ME3.
Last but maybe not least: the squad. Okay, it was very diverse and I love that, but as I already pointed out, maybe too much too was spent recruiting for the mission rather than actually doing the mission. I think next time, you need only have a maximum of 8 squad members, excluding Shephard. And Tali and Legion are great, but why do they come into it so late? It would have been very helpful to have tech experts earlier. Thank you for bringing back Garrus and Tali - good move.
Finally, keep the Mako dead, but bring back elevators. I miss the humour.