While on a lot, quickly press B, Z, Up, Down, B to spawn the Cheat Gnome. The Cheat Gnome appears at different locations, depending on which island you are on.

Find the Cheat Gnome, then enter one of the following codes to unlock the corresponding option on the Cheat Gnome:

Code Effect

Quickly press 2, Up, Right, Z, Right. Add One to Skill.
Quickly press A, A, Down, Down, A. All Crafting Resources.
Quickly press Minus, Plus, Z, Z, A. All Motives.
Quickly press Plus, Plus, Minus, Minus, Z. All Plans.
Quickly press Left, Right, Left, Right, A. Maximum Current Food and Resources.
Quickly press Z, Plus, A, B, 2. Maximum Relationships.
Quickly press Z, Z, A, Z, 2. Unlock Vest and Tanktop.