Complete Episode 1 - "Culture Shock".

Complete Episode 2 - "Situation: Comedy".

Complete Episode 3 - "The Mole, the Mob, and the Meatball".

Complete Episode 4 - "Abe Lincoln Must Die!".

Complete Episode 5 - "Reality 2.0".

Complete Episode 6 - "Bright Side of the Moon".

Complete all episodes of Sam & Max Save the World.

Heard 10 different comments about your unicorn.

In Episode 2, achieve six different cow identities that Mr Featherly will play along with.

In Episode 3, get a perfect score on Whack-Da-Ratz.

In Episode 4, find the Easter Egg.

In Episode 5, attempt to chop up everything in the text adventure with your +2 sword.