The Carnival of Chaos Add-on for Overcooked! 2 has 6 achievements worth 475 gamerscore.
Add mustard or ketchup to a recipe 100 times
Get 3 stars on all Carnival of Chaos levels
Get 3 stars on every level in Carnival of Chaos World 3
Deliver every type of meal in Carnival of Chaos
Get 3 stars on every level in Carnival of Chaos World 2
Get 3 stars on every level in Carnival of Chaos World 1