Mass Effect 2
… I actually completed Mass Effect 2 a few weeks ago, but following that I started up a new character and played through it again. Like Mass Effect it is very immersive and responds to how you play the character, and I felt that I needed to choose the other moral path offered by the game and see if it was just because I played the game as intended or if it was indeed that good. It was, but knowing what parts where changed and what were not made some of it feel patched together.
So, Mass Effect 2 is a good game. A great game even, an improvement over an already solid first iteration. The classes and abilities have been more clearly defined, the equipment and item system have been trimmed down to something more suitable to the game and the seemingly auto-generated planetside segments have been removed in favor of a large number of solid sidequests with proper level design. The story and the presentation of it feels even tighter now than it did in Mass Effect, and the characters feel more rounded and likable.
Nothing is really horrible with the game (I did not mind the mining so much as others seem to, but then I did that while I was eating), but there is still ways to go with the battle system. It has improved since Mass Effect to be sure, and considering the multitude of ways you can play the game it does the 3rd-person cover-based shooting game fairly well. Doing everything seldom means doing anything particularly good, though, and the AI rarely do what you tell them, the cover system often means your character jumps in and out of cover without being told and being shot in the process and there is a sluggishness to the movement. Also, the game has the same rendering issues found in Mass Effect as well as a bunch of physics issues, getting stuck in terrain is not at all uncommon.
But you get the feeling Bioware was aware of this not being the core of the game and made the battles suitably lenient. The game is very well-designed and immensely enjoyable, and considering the game with the best cover-based combat I have seen was Gears of War maybe asking for an improvement in that area is risky.