Get the indicated amount of orbs while playing a game to unlock one of the following cheatcodes:

5 orbs - Toggle Jak's Goatee
15 orbs - Mirror World
30 orbs - Big head mode
45 orbs - Small Head Mode
55 orbs - Scrap Book
65 orbs - Scene Player Act 1
75 orbs - Vulcan Fury Course
95 orbs - Scene Player Act 2
105 orbs - Peace Maker Gun Course
125 orbs - Scene Player Act 3
135 orbs - Reverse Races
145 orbs - Level Select
155 orbs - Infinite Ammo
165 orbs - Infinite Dark Jak
175 orbs - Invulnerability
200 orbs - Hero Mode [*]

[*] Hero Mode will allow you to start a new game with all four morph gun attachments.