Left 4 Dead 2

Left 4 Dead 2 is a cooperative first-person shooter where players fight through waves of zombies across campaign missions. Released in 2009, it remains playable on PC, Mac, Linux, and Xbox 360.

Recently, the game's creative lead revealed that Valve deliberately leaked the game's trailer during development because the ESRB had blocked its official release. The team worked around the restriction by distributing the footage through unofficial channels, a workaround the developer joked couldn't cause problems two decades after the fact. The anecdote highlights some of the production hurdles the studio faced bringing the game to market.