More of a glorified tech demo than a great game
For a First Person Shooter I've never had so little to shoot at, there is very little variation in the types of enemies you encounter and don't believe what you here about enemy A.I. during combat - They have the intelligence and tactical awareness of organic vegetables even on hard difficulty. Seriously they just stand completely still and take pot shots at you no matter what form of devastation you're raining down upon them, they'll only look for cover when reloading which takes them a good while as well.
Eventually you will be followed by squad mates, squad mates you'll eventually murder in cold blood because all they're good for is bait and getting in your way every 5 seconds (The developers made a big emphasis on the fact they can do things on their own and fight for themselves, hahahahaha! ha!)
Gameplay really seems to be on rails, very linear, very straight forward, very little variety or choice in how you approach situations (hardcore FPS fans may be miffed by this). A lot of the time you'll be glad to finish some levels just to get them out of the way and find somewhere far more interesting to battle through the adventure. The weapons at your disposal leave much to the imagination and dont exactly deliver much of a punch either, but the gravity gun makes up for it in so many wonderful ways (if you can pick up an object you can fire it, great fun).
I really wanted this to be a great game because I loved the original and followed the progress of this very closely, but ultimately I feel a little let down by its lack of being a good FPS. But Like I said the eye candy makes this title worth its weight in gold..... although if you never play Half Life 2 in your entire life you wont have missed anything.
A lot of people will love this for its style and delivery but any seasoned frag em up veteran will feel very underwhelmed by its content.