The game is great, full of novelties: new online modes very nice and somewhat diversified the gaming experience as Scavenge where to collect cans of gasoline, how much realism which makes the single player campaigns, of course we found the traditional modes like versus (two teams of four compete), where survival must be taken as long as possible against waves of zombies and classic co-op mode.
In terms of content, there are some new special infected well thought renewing the experience without any change either, rendering maps is very nice (the improvement is there but is not extraordinary), the locations traversed during Missions are varied but much less frightening than the maps from 1 L4D.
The final game is very good, but it is true that it looks more like a big extended L4D that a complete set. If you liked the 1st, you'll go for worship, and if you do not know the franchise and you're ready to battle hordes of zombies to blow chainsaw, machete or shotgun this game n 'more than expected you.
Warning: this game is playable exclusively online and require the mandatory installation of Steam portal.