There's nothing really wrong with F.E.A.R. 2 but it's just not that great.
Enter F.E.A.R. 2. To Monolith's credit they attempted to recapture that feeling of being powerless to the greater forces of the unknown by having you play a totally different character who is going into basically the same situation with no prior knowledge. The problem is if you've already played the first game you know everything that is going on, what you can expect from visits by Alma, the general plot, and where you fit into things. The horror element went right out the window and we are unfortunately left with a decent first person shooter with the occasional grotesque enemy. For someone who hasn't played the first game, don't worry, they catch you up pretty quick on what's going on, you won't know all the details but you'll know enough to know things have gotten a little more stupid this time around.
Before I continue let me just address the one thing that bothered me the most about F.E.A.R. 2 however trivial it may be. Replica soldiers are designed to be wielded by a psychic commander, like Paxton Fettel from the first game, and as you learn in the second game the creation of such commanders is a major problem for the Armachan Corporation. In the first game this made sense, Paxton Fettel controlled the Replica soldiers. Without him they were nothing. In the second game they are lead by an ambiguous commander and squad leaders. Yes they gravitate toward Alma's psychic callings but otherwise they seem completing capable of both receiving orders by word of mouth through a headset in their helmets (confirmed in a intel file you find in the game) and by orders received from other Replica soldiers. Very often throughout the game you'll hear dialogue like "What's that sound, you there! Go investigate!" Wait...these things can think for themselves, can order one another around, and show at least some basic problem solving skills? What the hell is the point of a psychic commander? End rant.
The classic F.E.A.R. gameplay has been retained more or less. There's no longer leaning but it's not a terrible loss. There's a decent variety of weapons but they're pretty bland to use. The great melee attacks make a return but sadly like in the first game are pretty useless. Slo-mo returns but by this point the visual charm and cool-factor has worn off so its more of an instant win button to get out of some of the games slightly more challenging firefights. Speaking of difficultly on normal difficultly the game is an absolute cakewalk if you're familiar with first person shooters, so if you blast through these games frequently you might want to crank that up to hard. There's multiple grenade types and two somewhat entertaining power armor sequences. I say somewhat as these sequences are so easy and linear it's not really all that interesting to just amble along shooting everything that walks in front of you into red paste for five minutes until you reach your destination.
The story despite the butchering of the Replica soldiers concept is still good enough to get you through though some of it seems to assume you have knowledge of the events from the first game. The final scene carries some sufficiently disturbing implications for the sequel and the jump scares are occasionally pretty good.
F.E.A.R. 2 isn't a bad game. It's certainly not as good as its predecessor but is a decent first person shooter with a few jumps in it. Any first person shooter fan will like this but don't expect greatness.