Overcooked! 2

You have to get 3 stars in the 6 levels of the world 1 (in addition to the tutorial). You don't need to do the Kevin's levels.

Here is a playlist containing videos of all levels unlocked in 4 stars duo mode. They will show you the technique to use, but you just have to make 3 stars for this achievement.
https://www.youtube.com/playlist?list=PLTg8yNY-9NDMNpQs1RLGR...

See also below the 6 levels separately. Good game.

Level 1-1
Level 1-2
Level 1-3
Level 1-4
Level 1-5
Level 1-6

Here's a walktrough of all the levels in World 1 with 3 stars.



Level 1 - 0:00
Level 2 - 3:40
Level 3 - 7:25
Level 4 - 11:05
Level 5 - 14:55
Level 6 - 19:25