This game reminds me of several titles: Dragon Age 2 (how the maps are confined), Witcher 2 (combat), and Mass Effect series (story/quest branching). For a traditional RPG it's got some things right, but it has its share of problems.
1. Tactical combat. Combat gets even more challenging and fun at Extreme difficulty, but at a price...
2. Nice setting and atmosphere. Mars here is like a remnant of some former colony; a fresh change from those high-tech ones. Everything is rusty, red, and make-shift. Put it another way, it's more like an apocalyptic Mars.
3. Your choices matter. People may die/live, quests may be locked/opened, etc... If you like replaying for different endings then this is for you.
1. At Extreme difficulty, a bad selection of skills will make the game almost impossible. There seems to be some skills that must be unlocked first, such as Evade, Sneak, etc.
2. No crowd AI. At hubs you may get invovled in battle, but civilians do not react at all, even when the fight is happening right under their noses. This hurts the sense of immersion.
3. Some quest are hidden inside branching conversations and are easily missed if you choose the wrong reply (but you have no idea of the difference). Choose between "just say it!" or "ok ok i got it"?
4. Characters and lore are rather under-developed. For an RPG of this length (30hr for me), you only get to know a few of the characters. Some just pop up with little background info. The romance here is merely a filler.
5. In combat you only have limited control on your companion (only 4 "states"), which sometimes is not that helpful.
Despite the cons, I still enjoy this game a lot, primarilly for its combat and story. If you aren't that picky about graphics and AI and just expect a down-to-earth action RPG, this shouldn't disappoint you.