Just completed this, thoughts below:
+Visually very impressive for a game that's over 5 years old; I can't think of many pre-Crysis games that look this good. In particular the Steelworks level has a nice gritty feel to it, foilage looks good, and flames are handled well.
+Excellent framerate throughout, constant 120fps maxed out with 16xAF and FXAA even on a GTX280
+Some very big missions, I think the refinery and steelworks levels must have taken me around 2hrs each
+A few boss fights which are reasonably varied
+I quite like the game mechanic of recovering health from dead bodies, it makes you weigh up risking it during combat
+Combat is satisfying for the most part, which is pretty key in a game like this.
+Some nice set pieces throughout where enemies flood into a big room and you have to make use of cover, manoveur to get a good angle on a hostile turrent, choose how to use your powers etc
-Voice acting is very wooden and cliched
-Plot isn't that convincing i.e. you start the game getting attacking by your former employers for no apparent reason, and then literally make a deal with the devil with very little convincing!
-Autosaves are far too infrequent; if a level takes about 2hrs to play through it needs more than 3-4 autosave points.
-Most of the powers are a bit contrived, for example the 'teleport' (which isn't actually a teleport, more astral projection) to hit switches you can't access
-Felt like it could have used fewer, shorter missions - in general if a level in a shooter game takes me longer than about 45mins I start getting restless. 5 missions isn't very many.
-AI teammates are underused (basically only the final mission) and generally a bit useless
-Confusing ammo counter, it shows ammo in current clip and total ammo, rather than ammo in current clip and ammo NOT in current clip like 99% of games do (so if you see "12 24" that means you have only 24 bullets, not 36). Compounded by the fact that reloading discards any ammo in current clip!
-Could do with a bit more guidance in places e.g. hints on how to fight bosses, I had to resort to a walkthrough guide a couple of times. As mentioned above the "teleportation" power needs more explanation, I didn't get it at first either...
-Possible to get stuck when jumping around near non-uniform edges such as crate piles (if you've forgotten to quicksave recently this can be VERY frustrating!)
Overall I'm fairly impressed, can't think of a third person shooter I've enjoyed more, and certainly better than the likes of Rogue Trooper, Lost Planet, Just Cause etc.