The Good: Amazing visuals, gameplay, boss fights, and story, lots of replay value, co-op is a blast
The Bad: Sheva's AI can be questionable some times, to similar to RE4, shorter than RE4, just isn't RE4
I was waiting for this game ever since I stepped foot into RE4 2 years ago (on the better PS2 version). For some reason RE5 feels like RE4.5 since it feels so similar and this was a big disappointment for me. Don't get me wrong RE5 is phenomenal, but all the similarities can make avid RE4 players quickly bored and/or not so impressed. Rewind four years ago to that pre-rendered still of Chris Redfield during the RE5 announcement and look (or remember) how amazing it looked.
Well since it took so long to come out RE5 now looks on par with most next-gen games. It IS one of the best looking games out right now, but what RE5 does that RE4 didn't do was amazing cinematic cut scenes. RE4 had a lot of interactive cut scenes, but RE5's are very cinematic (buy the collector's edition and you'll see the new camera technology they used to make these amazing cut scenes). There are fewer interactive cut scenes (press so-and-so button within 2-3 seconds), but everything else makes up for it. RE5's controls and basic gameplay are exactly the same as RE4's. Hey, if it ain't broke don't fix it right? There's still the over-the-shoulder camera along with the whole laser sight and the whole wonky control scheme. While it still works it does feel dated and I wish there was a more Gears of War type control setup or even something more modern.
One of my main gripes is you attache case is a whole lot smaller and you can't upgrade it like in RE4. Sure you have a quick select button, but I'd prefer more room for stuff thanks. You get nine NINE slots and they are quickly used up. Let's say you have a vest, four different weapons, and four ammo types there's no room for health (yes it's still the stupid herb ordeal), grenades or anything else. This requires a lot more sacrificing, but thankfully your sexy buddy, Sheva Alamar, has nine slots as well so you can trade and exchange items with each other. Yes, there is a "buddy system" and I think in zombie ridden Africa the buddy system is great (don't worry it's not a "bodyguard" system like RE4 Sheva actually fights). Sheva's AI is pretty good...sometimes she tends to try and shoot through you half the time and doesn't like to keep up with you when you're bombarded with enemies.
Rarely will you die from this but if you do you get mad. This is why RE5 is better played co-op online or offline. This is great and even has a Left 4 Dead feel since you're surviving zombie hordes while trying to stop...err...a really bad man from unleashing the new Uroboros virus around the world. Since this is on a next-gen system the boss fights are bigger, badder, and tougher and boy do I mean BIGGER!!! You thought the El Gigante was huge on the GC, PS2, and Wii try shooting up a 30 foot flying B.O.W. or something that's the size of a naval freight ship. A few new elements are added to certain boss fights such as "key weapons" and these are only good for that fight. You may have a rechargeable flamethrower, RPG, or even a satellite gun kind of like the Hammer of Dawn in Gears of War. While all boss fights are a major challenge you can always do it in one try. There are a lot more weapons in RE5, but most of them are useless since they are slight variations of other weapons. It takes longer to completely upgrade weapons and you can only do this when you start the game, die, and in between levels. No there's no creepy British dude with stuff under his coat selling you things. I found this change a bad one since it may hinder some people when they need a weapon before a certain point. Upgrades cost a lot more and thus makes unlockables harder to get.
Another great thing about being next-gen is the levels are now HUGE and the puzzles are challenging, but not confusing and scatter brained. There are a lot of little goodies to collect and unlock. You can use points from achieving certain things (such as finding all BSAA emblems, beating certain levels etc.) to unlock figurines, filters, costumes etc. These add great replay value and can make the game more fun a second time. When you beat the game you get a Mercenaries mode (like in RE4) that pits you against tons of zombies you have to fend off. RE5 is an amazing game, but feels too similar for RE4 veterans and may hinder and bring down your expectations.