You can use the guide below but the achievements are not ordered in obtainable order, so that will make it harder to keep track of when you are going for a certain achievement in a specific level. If you don't want to miss any achievements in Single Player then click here for a list of all missable achievements in obtainable order with a video and written explanation for each achievement. Out of the 29 achievements, there are 14 story related achievements worth 185 and 15 missable achievements worth 290. There are a total of 29 achievements for Single Player worth 475. There is no difficulty for Portal 2 so you don't have to worry about that. You will only need 1 playthrough for each Single Player and Co-Op, with a few Course/Chamber replays for Co-Op. There are no collectible achievements, only level specific achievements, story related achievements and a few misc achievements.

This game is split up into two sections: Single Player and Co-Op. Now sit down and get ready to feel that sense of accomplishment again, and expect to be laughing the whole way through. Valve has kept it's promise and made the game more challenging, more fun, and even more hilarious. With more environment interaction, and a brand new Co-op system, Portal 2 will keep you on your toes from start to finish, and even after that. Welcome to Portal 2, the highly anticipated sequel to 2007's Game of the Year, developed by VALVE. Does difficulty affect achievements?: No Difficulty Do cheat codes disable achievements?: No Cheats

Number of missable achievements: 30 (15 Single Player / 15 Co-Op) Minimum number of playthroughs needed: 2 (1 for Single Player 1 for Co-Op) Approximate amount of time to 1000: 10-25 Hours (Depends largely on skill)

Portal 2 coop level 6