Left 4 Dead 2 is nearly 12 years old as of the release of the blog post, and it is still remarkably popular despite how old it is. Only released exactly one year after the original game, Left 4 Dead 2 was widely praised by critics and fans and is still held in high regard as being one of the zombie games ever made.
If I were to analyze this game, I would look into multiple areas. I would investigate how a studio would deal with the backlash of releasing a sequel immediately after the first game was released, how they would improve the concepts built on from the first game. For example, if any new special infected would be created and how they could affect the momentum of players as they played as either survivors or the special infected themselves. Also, how they would improve the multiplayer experience, by adding in new modes to play, creating servers that allow for strong internet connections so players could enjoy the online play.
Another area would be the inclusion of the A.I. director, a system that controls how many infected spawn and where they spawn, how and where items are spawned, special infected numbers, including tanks and witches, even altering the map. The questions would be regarding the focus on creating a unique play-through for the players, where each time they would play the game, each experience would be completely different, and how the A.I. director controls it.
Another question would be on the game developers create a game where players must play as a team to be successful and win at the game. Certain special infected pin the survivors and leave them helpless, forcing their teammates to help them if they want to move forward and win the game. However, there can also be situations where there may be too many infected near a downed teammate and they must make a choice too leave the player to die to win. These tough choices, and the systems designed to create co-operation amongst the team playing as both the survivors and the infected.
This framework would be how I would analyse this game.