Long Live The KingG 20

OK, here is the fastest way to get this achievement. Since you do not need to beat full chapters, I have listed the missions required from each chapter. This way you can get this achievement in about 30 minutes or less.

First, put in the cheat code WELDERSBENCH to unlock all chapters.

There are 8 chapters needed to beat. Each will raise your achievement progress bar by either 12% or 13% (12.5 x 8 = 100%), make sure the bar raises before moving to the next chapter.

Hangover - this is the tutorial, so beat this one easy then go to chapter select for the next ones.

Bat's Tower - only need last mission 'Bullfish's Revenge'

Barn Boys - you need to do missions 'Frying Pan' and 'Slam Dunk'

Sloprano - only need last mission 'The Bluff'

Uga Buga - only need last mission 'Buga The Knut'

Spooky- only need last mission 'Mr Barrel'

Its War - only need last mission 'Peace At Last!'

Heist - only need mission 'The Vault'

Those missions are the only requirements for the achievement. You do not need to play anything from chapter "Windy".