ME2 was not particularly good. The characters were good, but the gameplay was severely dumbed down and the main story was flat out bad. I don't know who at Bioware thought it was a good idea to force the player to work for Cerberus (basically space Nazis, for anyone who hasn't played Mass Effect), but it wasn't a good idea. You can't just railroad the player into working for bad guys in a game that is supposed to celebrate player choice. Not only that but they mishandled the villains, and the entire Collector plot was a waste of time that didn't contribute to the overall story. ME2 was the beginning of the decline in Bioware's quality and it never stopped after.