I’ll start off with that, so far, I really enjoy Left 4 Dead 2. Â L4D2 had a lot of negative feedback from fans of L4D1 since it was released only a year after the initial title. Â L4D1’s content was sparse and most of us fans purchased L4D1 on the assumption there would be more content added for us for free or a reasonable price. Â Instead, very little was released and L4D1 feels content poor; the solution is to buy the fully priced sequel that appears to be little more than an upgrade or expansion pack.
From what I’ve played, L4D2 both defies and meets these expectations.
Technically, L4D2 feels like a sequel.  It is still the same Source engine underneath, but there are enough tweaks to the graphics artistically and technically to feel like a new game.  The zombie gore, especially, has been amped up. Not only do the new melee weapons pack punch, but any of the weapons now stand a chance of severing limbs or leaving a very bloody wake in their path.  Level details during the day, and the basics of fire, water, and trees all look like a nice upgrade over the previous game’s single palate presentation. With the introduction of several new carry-ables, several new types of guns and melee weapons, the new maps that all feel longer, and the new modes of play included in the box, L4D2 is far more content rich than L4D1. If you could justify L4D1’s price and enjoyed it, then L4D2 is a no brainer (zombie humor intentional).
L4D2, however, was very clearly designed for the fans. Â From a gameplay design point, L4D2 feels like a really well done expansion pack. It has more than enough content to be considered a full game, but the difficulty and complexity are both higher than the original title. Â This was clearly made for fans who mastered l4d1. New players will hit a high difficulty and learning curve.
In L4D1, you could introduce the game to new players on Easy difficulty and regardless of their skill you could push through at least most of the campaign (and probably win).  You only needed to describe a couple of weapons (shotgun or machine gun), and a couple of carry-ables (first aid and pills).  The most complex part of the interface to describe was that you could only carry either the pipe bomb or the Molotov cocktail.  In L4D2, new players are greeted with a far greater variety of weapon and carry-able combinations, but will not instinctively know which items will force them to drop others. Is the chrome shotgun better than the pump action? Is the auto shotgun better than the combat shotgun? Silenced vs un-silenced uzi?  Where did my first aid kit go? I had to pick it back up after picking up and deploying an explosive round ammunition station?  And while they are learning all of this, they will be greeted with hazardous environments where stumbling off of the path will set them on fire, or drop them off a bridge which separates them from the group and makes it difficult to meet up since the swamp water slows them down. The new infected also double the number of specials new players must quickly learn to look for, and all of which seem more lethal than their L4D1 counterparts.
To sum up the first game of L4D2 I played, it was on Easy difficulty with a crew familiar with L4D1 and we all died in the first campaign before the finale from some well timed Spitter shots and fire.
So, coincidentally, the core group Valve angered by releasing this game so soon is clearly the target audience of this product.  L4D2 is not for introducing new players to the series; it is to provide a 2.0 upgraded experience to those who enjoyed L4D1 and had already mastered the level layouts, sound byte warnings of specials, and were growing bored with the limited content available in the initial title.  They even released it as a rival to the juggernaut that is CoD: Modern Warfare 2, which is suicide if you were to compete for any average FPS player.  But they were confident their fans would come. Hopefully they were right.
Now that we got that comparison out of the way:
- Why do people complaining about length? When I hear conplaints about how short L4D1 is, I nod in agreement. Whenever I’m playing, however, I’m hoping the safe house is right around the next corner and just want it to be over. Please, just don’t let there be another attack! L4D2’s campaigns feel longer, and in the last finale I played, there were two tanks both simultaneously and next to each other as the final wave. You had to kill both to proceed.
- The new melee weapons are all very fun to use, but I also really like the new Magnum. Â It’s like the hunting rifle without a scope and unlimited shots.
- The new cast of characters has more personality than the old group, but aren’t as endearing.  Ellis has a lot of great dialog and I personally enjoy Nick’s cynicism, but they don’t quite match Francis’ pessimism, good old Bill’s humor, or Zoey’s “I’m a cute college girl but I’m also independent and strong” attitude.  Maybe they’ll grow on me.  I just hope they release a patch that let’s you pick between any of the 8 for Vs multilayer; that way we won’t have to all fight over who plays as Francis or Bill.
- Rock on, Midnight Riders! Rock on! (fun finale where you throw a rock concert to gain the attention of a helicopter and all of the nearby zombies).
- More zombies is always more fun. Â The new infected make Vs mode much more enjoyable. Â Now you won’t be stuck as the hunter several spawns in a row.