I need... HAAAAALLP
Just in order to get straight to the point, I'm going to go out on a limb and say that if you liked Resident Evil 4 (and you should have) you will almost certainly enjoy Resident Evil 5. This is because the basics of the game are essentially unchanged for Capcom's newest zombie thriller. Everything from the way the game controls to the way the environments are set up to the way your enemies try to take you down is extremely close to what you find in Resident Evil 4. The crazy frantic fight for your life across this games length will almost certainly have you in nostalgia mode about that one time in Resident Evil 4 when you took on those 100 zombies with just a pistol and a knife.
But this isn't Resident Evil 4, this is Resident Evil 5, and while the similarities are abundant, it is still a different game. The most obvious difference to any fan of 4 is the inclusion of your (this time somewhat capable) lady friend, and the ability for the entire game to be played on cooperative mode. Seeing as how I have no friends nearby who care about good games, I wasn't able to play the game on co-op at all, and this is where Resident Evil 5's greatest shortcoming becomes apparent. You should play this game with another person if it is at all possible. The AI for your wonderful partner Sheva is just not up to the task of responding to a zombie army the way a rational human would. I felt like I had to worry as much about micro managing her movements and actions as I did actually fighting the enemy. It certainly made the game harder, but not in a good way - rather in a way where I felt like I had to play against the game rather than within the game. This problem is non existent if you have cool friends, but if you're like me (sniff), you'll find yourself wishing they had just had an option for single player only that takes Sheva out of the picture, because she really just gets in the way.
Despite that being a serious problem, this game is still a part of that genre that is 100% masterable, and therefore you can learn to master controlling your AI, and it will become less of a problem the more you play. The game also rewards you with playing more by letting you unlock and upgrade guns as you go, and you can take those upgrades to any level on any difficulty. This is kind of strange for Resident Evil, because one of the most stand out features of 4 was the pacing of the game, and how you found and upgraded guns through your playthrough, and once it was over you couldn't jump up to the next difficulty with fully upgraded stuff. In 4, each playthrough was a standalone game, where you tried to find more effiecient ways to upgrade quicker, where in 5 it becomes more about how many levels you've played. This more arcade style setup works just fine though, especially when you consider the fact that professional mode (the hardest difficulty) requires that you have some pretty ridiculous weaponry to survive through.
Overall, this is a slightly shorter game than Resident Evil 4, but it's still jam packed with pulse pounding action and great environments, weapons, and enemies. The Resident Evil 4 formula is still holding strong, but I wonder how many games we can see it in before it starts feeling too dated.