If you can get over the old school controls and the dumb coop partner AI, you'll likely find Resident Evil 5 a great game. The only thing the controls benefit from is to make the player feel like playing the old RE games once more, but good thing everything aside from that is already up-to-date. I really liked the rocket launcher look like the ones used in real life and not that four slotted one that I wonder how the hell a girl as slim as Jill could carry that thing. The visuals too are also amazing that sometimes I get hit because I was distracted by the real-looking scenery. Now for the coop AI part, I wish it could've been better, I hated that Sheva always run ahead just to destroy those crates when I'm trying my best to stealth our way across the enemies. And sometimes she helps me sometimes she don't which kinda sucks as it makes me feel lucky if she'd saved me from an enemy; which brings us now to the online coop part which will definitely make things better because two heads are better than one head with an AI.
The story of course is amazing and for those religiously following the series will finally bring you a nice narrative to what happened to their original enemy. Now regarding achievements, this is an easy 930GS I could say as the only hard part of the game is the professional difficulty, and finishing that nets you the final 70GS for your perfect 1000/1000. The game becomes easier once you have the infinite ammos; and also by finishing it under five hours will give you the infinite rocket launcher, but still even with those bonuses the pro difficulty will still give you a hard time.
Final words, if you've liked the previous RE games then you really should try this one out, and also for those who have yet to try an RE game but liked the RE movies, I'd say this is better than the somewhat off-story in the movies. Resident Evil 5 is available for the Xbox360 and the PS3.
For help in achievements, take look at this link: Resident Evil 5 Achievement Guide.