If you dig zombie culture, this is as much a must have as L4D2.Requires more aiming skill than L4D2,but also not as fast
What are the main differences?
* You have iron sights
* Each map is kind of like a deathmatch zone where you have "inbound" swarms, then you go buy some weapons/restock, then do the next swarm, and so on until the map's BOSS comes out to play, and that's how you win a particular map.
* There isn't any real story like L4D. No objective beyond "kill 'em all and stay alive" in any given map, no charming characteristics to the survivor you're playing as either, or the people you're playing with.
And if you're in Australia, like I am... the gore factor is far more satisfying than the forced censorship in L4D2 (which if you try the unban trick, the L4D2 looks like so much more fun, but suddenly becomes crippled for online play, no one/servers ever seems to run it in uncensored mode). There is definitely something "right" about seeing blood splatter and flesh explode when you pop a zombie in the head, or blow/severe the limbs off of it.
The visuals aren't cutting edge but if that's what matters to you, go buy a console and voip with the other annoying kids that think "graphics" are what make a game great. The visuals in this are dark, dirty... gritty suits the theme. And there's enough high quality texturing and bloom effects to NOT make this feel dated.
PLUS it doesn't take up too much HDD space. Around 1.6gig versus L4D2's almost 8gig.
Zombies, mutant zombies, cyborg zombies... crawlers. There's a decent amount of variety, and like L4D2 you have "uncommon" zombies in the swarm mix.
Like L4D1 or 2, this game is rather boring if you play alone. There's no real sense of satisfaction when playing with bots at your side. It's when you have real people that it really feels good.
So this game shouldn't really be considered a "Singleplayer" even though it says so on the Steam store page. Singleplay if you're really keen to learn the maps before jumping into a server match... or just join a beginner server. Definitely don't jump onto a "normal" difficulty server because coming in fresh will get you killed.
The weight issue (how many weapons/armour you carry effect your movement speed), the Perks/XP system, the slow mo moments and easily getting lost if you're absolutely new.... Normal mode is a decent challenge for the experienced player, and the higher difficulty is exactly what games were meant to be on hard... hardcore.
Co-Op/Multiplay... this is what the game is all about and it can be as much fun as L4D2, just in a different no-shooting-from-the-hip kind of way. It's definitely more satisfying than L4D2 when you look at it from an FPS-skills perspective... Iron Sights make a huge difference. But it's also less dynamic than L4D2... it's really just a zombie genocide that doesn't run as fast as L4D, swarms aren't as uniquely different each time you go through a new match in L4D2.
It's not a replacement for L4D2 that's for sure. They're both well worth having for the different ways they satisfy, and the very different focus of gameplay (keep moving vs. survive each swarm in this zone)
It's worth the normal price it sells for on Steam, but if you see it on special you should definitely grab it. If you dig L4D2 and like a real aiming challenge in your FPS games, you'll dig this.