Had it for a day now, and have already made it through the Prdator campaign, and played a good few of the Xeno and Marine levels. I have to say I actually like it. A lot.
A few of the points made in reviews I have seen seem to have been made either without thinking through what the game is actually trying to do, or as a result of comparing it to other FPS games that really, can't fairly be compared to it. For example, the main criticism levelled at the alien levels is the controls. Yes, it's damn fast and it can get disorienting shifting from surface to surface quickly. Here's the thing though - that's the whole damn point. To get good at playing as the xenomorphs, you will have to get accustomed to being able to do this. And while it is occasionally glitchy with the R2 button, I haven't found it to be a game-killer of an issue. With a bit of practice you do get used to the insane speeds that the xeno's can get up to and timing your press of the attack buttons so that you strike your target as you hit him or her at what feels like 300mph does eventually come with practice.
So there is no auto-aim or iron sights. Big deal. The time it takes to ADS is about the same amount of time it takes a xeno to cover oh, I don't know, about half a fucking mile so it's no great loss, certainly on the early levels. And exactly how frightening would it be being stuck in a dark area with fast moving aliens around you when all you had to do was use the motion tracker to point in roughly the right direction, press the ADS button and get a perfect lock MW2 style every time? Or am I the only one who thinks that being gifted with an almost perfect shot every time might just detract from the whole "They're coming outta the walls. They're coming outta the goddamn walls. Let's book!" part of the experience? Maybe I've just been playing games for too damn long now and can remember a time when games made us work for the win as a matter of course, and not because they were "poorly designed".
The only real gripe I actually had was a feeling when playing as the Predator that I couldn't jump to some places where common sense would seem to dictate that I should be able to. Mildly annoying, but again not a killer issue. On the other hand, I defy anybody to tell me that they did not get a lovely tingly feeling all over the first time they sat up a tree with the IR vision mode on and let rip with the Plasma Caster.
As for the so-called "Fuck You" button - it seems to rely on A) getting close enough to your target to actually use it and B) the target being either unarmed (in which case how difficult a fight is it going to be for a Predator/Alien vs an unarmed human), unaware of your presence (ie "ITS BEHIND YOU!" style moments when you grab em) or reeling from a melee attack (or running away, in which case serves em right for turning their back on something so evidently intent on ripping them to shreds). First person melee combat is difficult enough to do without trying to over complicate things with 100-button Tekken-style combos I reckon. It seem's like a bit of an odd complaint though, given that certain other FPS games give you an instant "Fuck You" just by clicking in R3 within 5 metres of an enemy and the only time that gets moaned about is when people who don't like getting killed by anything get killed by it in MP.
Considering how hard it actually is to do first person melee combat, I reckon this game works pretty well. No, it is not perfect but it really deserve 5-7.5/10? I would say it was worth at least an 8.
The thing is, that to get the most from this game, I found that I had to lose the CoD "point and squeeze" mentality. Since doing so, I have had a great time with this game.