Easy As One Two Three

Easy as One Two Three is an achievement in Halo: The Master Chief Collection. It is unlocked by beating the par times on all Halo 4 levels. The achievement is worth 20 Gamerscore and can be unlocked on any difficulty.

Trivia
The name of the achievement means "Easy as (Halo) 1, (Halo) 2, and (Halo) 3".