Advent Rising was one of the most entertaining games of the year it came out. The game has a few buggy points (hanging off of ledges into the floor, elevators getting stuck preventing you from moving on), the gameplay more than makes up for these issues. The story was just enough engaging and the enemies were varied enough to add lots of variety to the fighting. Along with the powers and guns, the game can be very entertaining.
As a tip, if you find the sniper rifle, don't ever let it go.