Even though it's not the best RPG I'Ve ever played,it's easily the best TPS I've played.Not only is it a great game,but it's an entertaining fictional intergalactic encyclopedia because it's codex provides detailed information about history/cultural aspects of all the different alien races and about wars that have happened between certain races and how certain races first encountered other races.It will also teach you about extinct races and about races that were around tens of thousands of years ago.When you travel to different planets,you'll be shown data such as the population of the planet,and info about it's size,surface temperature,how long it takes to orbit it's star,it's day length,what materials/gases the planet is made out of and it's very fascinating.
Even though gameplay wise Mass Effect 2's gameplay is similar to many other TPS,it's worlds and environments are a big part of what makes the game stand out to me because they give the game so much atmosphere.whether you're in a beautiful metropolis on an alien world that has lots of flying cars flying around or on a world that's an industrial wasteland with powerful gusts of wind blowing across it's surface.
The characters grew on me because some of the alien characters have interesting cultural customs,or they have to rectify things from the past and one of the characters suffered a huge injustice that motivated me to help them.
The game has strong sexual suggestions and you can make Shepard have sex and I think Mass Effect 2's sexual related comments make the sexual inneundo in the Ar Tonelico games look tame.
The ending was epic because of it's intensity and story revelations and it was sad some of my party members died.