Missing some of the feel of the first two, this game seems a bit more like a rush to finish up the trilogy.
To be fair, the weapon options and fight sequences are rich and generally fulfilling other than some scattered segments that were had a somewhat annoying trial-and-error factor to them. Other than these moments, things moved along generally well with a full array of guns that you had to strategically use given the situations you were placed. While a few segments with the flying snipers were a bit annoying, overall the fighting is a bit more tactical than some FPSs.
As a story, this was a bit below average and cliche considering the deeper narratives of the previous two. While, overall, this series is not best known for its story one would hope that the developers would have pushed a little harder to wrap up the trilogy in an exciting way. Instead, from start to finish things just were a fair bit on the simplistic side and sometimes too cinematic considering the previous style choices of the first two games.
In the end, you feel a little jipped as you feel like you got a game that was mildly rushed. In each area, graphics, story, and gameplay things did just not add up to end this series in a way as fulfilling as one would hope. If you're a fan, certainly, go get it and finish up the series so you can have that sense of satisfaction of completion. However, be hopeful that the next round, if there even is one, will be bigger, better, and a better exclusive competitor for the likes of Halo and Gears of War.