Technical improvements and refinement of the combat to bring it up to shooter standards got the most attention during pre-release showings of the game and with good cause. Particularly on the Xbox 360 version the differences make playing the game a more comfortable experience than its predecessor. It's much easier to get caught up in the moment without the interruption caused by the action on the screen uncomfortably stuttering or graphical limitations causing pieces of the environment to pop into the scene.
Similarly, thanks to work put into the controls, the action in Mass Effect 2 now feels like a solid third-person shooter. And therein lies the first sign of an identity crisis for the game that continues to build the more I play it. Mass Effect 2 hits its stride at a quicker pace than usually associated with RPG's. Orchestrating my two squad mates and coordinating the use of our combined assortment of powers fits smoothly into the flow of the fight. Outside of battle, the streamlined conversation system does its part to keep things moving as well.
In an odd twist, it's the holdovers of more traditional RPGs that break Mass Effect 2's spell. Page upon page of written details about anything and everything in the world drag me down like quicksand. I love the lengths to which they've gone to create a complete world and can't help myself from reading it, but not a moment goes by that I'm not wishing I was back getting on with the game. The new planetary exploration system is an even worse offender. Ploddingly scanning planets one grid space at a time to find mineral deposits I need for various upgrades siphons off my enthusiasm in no time at all.
For as much as their explanation of the Bioware definition of RPG opened the door to a broader view of the genre, Mass Effect 2 illustrates the difficulties in turning that into a game. It seems caught up somewhere between the ideal of what this action/adventure/RPG style could evolve into and the practicalities of creating a game with an engine and systems that you know how to work with. So far I've been completely enthralled by the story and characters -- the heart of what I love about role-playing. Conversely, those old trappings of the genre feel outmoded here. I'm looking forward to playing the rest and gaining the perspective to look back at the game as a whole.