Mass Effect 2 is an excellent follow up to Mass Effect, in almost every possible way but that quality of focus comes at the expense of abandoning most gameplay elements that made the original unique.
The shooting mechanics have been completely overhauled, the villains are more interesting, the graphics are better, the biotic powers and the UI are more entertaining and easier to use, heck even the Normandy is cooler than before.
That’s also the only problem with Mass Effect 2. BioWare retooled this game into much more of a third person shooter with RPG elements than the original, which was an RPG with third person shooter elements. You can no longer freely explore planet surfaces, but are forced into the invisible-walled areas they’ve designed for the game. Fortunately those limited areas have been crafted to produce some great experiences, like the mission that results in recruiting Jack to your party.
You also no longer control the equipment your party uses or their skills to as great of an extent as the first game. While it could be a pain and eventually resulted in the all too familiar and ridiculous message that “your inventory is almost full” because you could only carry 250 items, in the first game you could manually choose your guns and armor, omintools, and attachments for every individual party member. Mass Effect 2 simply has no inventory system, at all. You can pick up anything and everything. If you want to switch guns, you would have to find a different one in the environment. Mass Effect’s inventory system was panned by many for it’s lack of organization and allegedly clunky interface, but it was completely usable and lent itself more to a functional RPG than simply not having one.
Combat is much easier this time around. Where shooting previously felt like an obstacle you begrudgingly had to knock out of the way in order to progress in the original game, in the sequel it feels much more like BioWare wanted you to enjoy the combat. In fact the combat feels so good, that it honestly feels like it was the primary focus of the game design, which is not a good thing. The FOV and camera angles are closer to Shephard so you can see the work they put into the animations. You can manually reload your gun now instead of having infinite energy, and you see the spent plasma cartridges as they eject from the weapon, hissing on the way down. The shooting effects and abilities like overcharge, or consumables like the ammo, feel meatier and enemies don’t just run at you until they die, which was often the case with husks in the first game with every weapon but the shotgun.
The paragon/rogue system is also pretty much meaningless in this game. You have to intentionally be a jerk at every possible opportunity in order to not get paragon. If you don’t commit to it, there’s no feasible way you could beat the game without being a nice guy. More importantly, Paragon and Renegade mean nothing to the game. They may present some differences in dialog options, but all they do is determine what little action cutscene plays during conversation when and if you choose one of them.
Mass Effect 2 also adds a resource collection minigame vital to completely experiencing the game. The Normandy can launch probes into any planet on the map, and use them to collect mineral resources. Unlike the first game where you have to obnoxiously drive the Mako up mountain sides and down into canyons and then jump out and manually interact with a vein of ore, all of that is done automatically by the probe. You use your scanning system, find an area that’s rich in resources according to the meter, and launch a probe. In turn, those resources are used to upgrade your ships weapons and defensive capabilities, as well as your own weapons and biotics. This also doubles as a replacement for the distress calls and other side quest type of content from the original, and, is often the only way to access certain quests in the game. Once you run out of probes, you can make your way to a refueling depot and purchase more for a negligible amount of credits.
Even so, the game is still good fun with a great story and great voice acting, with characters you can care about. If you aren’t already using it, please get the ALOT mod as it makes this an entirely different experience than playing it on console (even though it is just textures).