It's like a bigger Deus Ex, with a bit of Halo and Star Wars: KoTOR. A masterpiece.
The combat is satisfying with the use of squad tactics, abilities and weapon variations, with progressively good rewards. As an RPG game, the developers really hook you with constant showering of XP, big and small, with almost every thing you do, from completing quests, dispatching enemies, discovering new info to just having a conversation. This makes leveling up very frequent at an immensely engaging, yet comfortable pace.
The gameworld is littered with new discoveries and backed with in-depth info, from trivia excerpts to encyclopedia-style passages, making it a very believable world, even more so than Star Wars, the Godfather of Sci-Fi. I feel it's because most of it seems to reflect the real world that we're living in now, like their Council versus our United Nations, and C-Sec versus FBI/CIA, and when you care to read about some of the species' backstories and events, you would notice they're uncannily inspired from real-world history. Impressive and thoughtful!
Other than combat and errand running, another core gameplay is the exploration feature, which covers a vast span of solar systems, both fictional and real. Also, commanding the land vehicle is fun in terms of traversing and fighting. Other than all this, there is so many other optional stuff to do, which given the strong appeal factor of the game itself, you would feel obliged to attempt all of them, making it a majestic social-life-killing commitment. Be warned.
KingLim