Mass Effect 2 is a sci-fi action role-playing game set across planets in the Milky Way. You play as your own customized Commander Shepard, leading your ship and your squad to save the galaxy from the Collectors.
Pro Good romance subplots
The romance subplots in Mass Effect 2 are great. Playing as male Shepard, you can romance most of your female squadmates, while female Shepard can romance most of the male squadmates. If you romanced someone in the first Mass Effect, then that story continues here in Mass Effect 2. There are certain consequences for being unfaithful where your partner will confront you or the person you're cheating with in a heated showdown. Sticking with one person for the whole game rewards you with a romantic scene near the end of the story. A lot of care and attention went into these subplots, giving you the chance to see each of the characters in a new light.
Pro You can customize your protagonist Commander Shepard
There are lots of ways to make Commander Shepard feel like your own character. The character creator at the start of a new game lets you change all sorts of options, from your hair, to your skin color, the shape of your nose, mouth, and ears, and so much more. Or, if you prefer, you can simply stick with the default male or female Shepard. You also get to pick which class you want to be for combat: soldier, infiltrator, vanguard, adept, or sentinel, each with their own unique abilities, like the adept's helpful "magic spells" and the infiltrator's specialty with sniper rifles. You can role-play as Shepard however you want, with plenty of options to customize your looks and your combat specialties for whichever role suits you the most.
Pro Improved third-person shooting combat from the first game
The combat in Mass Effect 2 is much better than its predecessor in every way possible. You can enter cover and vault over it whenever you want this time around instead of your body magnetically sticking to whichever surface you stand next to. Guns use expendable thermal clips, which are like bullet clips, meaning you're no longer held back by your weapons overheating if you fire them too much. They also feel more satisfying to shoot with a real kick to them, especially the meatier shotguns and sniper rifles. Your squadmates are smarter this time around, like how you can order them to use their own abilities to chain them with yours for cool bonuses like melting armor with fire powers. The combat is actually fun in Mass Effect 2 and stands on its own next to the great story and characters.
Pro Your choices have true consequences on the story
Your choices have direct consequences on how the story plays out, not only in this game but also across the rest of the Mass Effect trilogy. In Mass Effect 2, you get to choose between options like keeping or destroying inhumane scientific research that could help an entire galactic race, or exposing the dark truth about a squadmates' family for the greater good or keeping it hidden. Who you bring along for the final mission and how you lead your team has a huge impact on the ending. Each of your decisions, big and small, carry over into Mass Effect 3, opening things up for many different playthroughs to see how things turn out with other choices.
Pro Memorable cast of authentic characters
Mass Effect 2 has an amazing cast of both human and alien characters who feel like real people. While just about any NPC you meet is fantastic, your squad members are the ones that stand out the most. You have about ten squadmates to choose from, not including DLC characters. They all have backstories and traits that are believable and natural. Their personalities shine through the most during their optional loyalty missions where you help them complete certain personal tasks separate from the main story.
One of your human squadmates, Miranda, is cold and intimidating at first, since she distrusts you for her own reasons. Her loyalty mission is unexpectedly emotional, showing Miranda as more flawed and caring than she lets on. There's also Garrus, one of your returning squadmates from the first Mass Effect. He's a turian that looks somewhat bird-like in design, but his easygoing personality is very cool, making him feel relatable and reliable. His loyalty mission shows his darker side as you help him tie up loose ends from his past.
Getting to know everyone through dialogue and squad banter is a lot of fun, making it easy to grow attached to your favorite characters.
Con The main enemies, the Collectors, feel misplaced in the trilogy
The Mass Effect trilogy's story is about stopping the Reapers -- ancient, unknowable beings who destroy all life -- but this gets interrupted in Mass Effect 2 by the Collectors who are more like minions of the Reapers. The Collectors are dangerous because they harvest humans, though this is not as important as the Reapers who seek to end all life in the galaxy in Mass Effect 3. It would have made sense for Mass Effect 2 to focus on the Reapers instead of the Collectors, since they're more of a secondary problem.
Con Levels are very linear
Mass Effect 2's levels are more like winding corridors with the occasional wide open space here and there. You always have a clear sense of where to go next, but there isn't much room for exploration. It's also obvious when enemies are about to show up, since you'll come to a place with a bunch of chest-high walls conveniently spread around the area for you to take cover behind. It's unimaginative, making missions feel like you're only going from point A to B.