Sonic Adventure Cheats

Achievements
Amy Rose (10): Become friends with Amy.
Big the Cat (10): Become friends with Big.
Chao's Best Friend (20): Get all Emblems of the Chao Race.
E-102 "ƒÁ" (10): Become friends with E-102.
Knuckles the Echidna (10): Become friends with Knuckles.
Metal Sonic (15): Get all 130 Emblems by playing Sonic Adventure DX.
Metal Sonic Master (15): Get Level A on all the Action Stages by using Metal Sonic.
Miles "Tails" Prower (10): Become friends with Tails.
Mission All Accomplished (20): Clear all 60 missions.
Sonic the Hedgehog (10): Clear the Sonic story.
Sub Game Master (20): Get all Emblems of the Sub Games.
Super Sonic (20): Clear all characters stories.
The Adventurer (20): Get all Emblems in the Adventure Field.
The Fastest & Strongest (20): Get Level A on all the Action Stages.
The Perfect Adventurer (40): Get all 130 Emblems.

Avatar Awards
These are unlocked for playing the game for a certain amount of time. Both awards can be used on either a male or female Avatar.

Sonic's Hi-Speed Shoes: Play for 10 hours
Vintage Sonic Tee: Play for 5 hours