Left 4 Dead 2 gives us some improvements but doesnt really impress as much as the original.
Good voice acting that is helped by funny (yet short) dialouge between characters, Good music, and solid sound effects.
Visuals: 8.5/10
Good character models and various environments that are hurt by the noticable bugs and glitches through out the game.
Playability: 8.5/10
Nothing new has happened for the combat system, Its the same one from the original game.
Delivery: 9/10
Campaign isnt as long as Id like it to be and the story isnt that good but the Multiplayer is greatly improved from the previous game.
Achievements: 9/10
Quite easy to get all the achievements in this game if you work at them, A lot of unique ones that are fun and challenging to get.
Overall: 8.5/10
Left 4 Dead 2 is a good and very addicting game that you will have trouble putting down.