Pandemic Legacy Season 2, Yellow Box
Pandemic Legacy Season 2 is actually a very different game than Pandemic. If you want a game closer to the original Pandemic I recommend Pandemic Legacy Season 1. This game continues the story that was told in season 1 while also offering you a very different game.
Be warned that you're expected to put stickers on your game board and cards so you can only play threw the campaign once. It'll take 12 to 24 games to complete the campaign, to be fair most people don't play the same board game that often ever anyways.
There is no difference in game play between the yellow or black box.