Here is the full list of all 30 Jet Set Radio achievements.
Use all graffiti in missions
Finish the game without anyone latching onto you
Unlock Garam and use him as a player character
Unlock Pots and use him as a player character
Unlock all characters
Unlock all songs in the bonus menu
Unlock Goji and use him as a player character
Unlock Noise Tank and use him as a player character
Complete every level with a Jet rating in all game modes
Collect all Graffiti Souls
Unlock non-masked Poison Jam and use him as a player character
Unlock Poison Jam and use him as a player character
Complete all missions with any rating
Unlock Love Shockers and use her as a player character
Tag at least one rival gang member within 30 seconds
Shove the two civilians in No. 540 level before the choppers show up
Complete Chapter 3
Complete a level without collecting a Recovery Spray Can
Perform a 100+ trick combo
Complete the tuorial
Complete Chapter 2
Complete Chapter 1
Destroy all helicopters in a level
Create your own graffiti in all sizes
Perform a Turn Trick in game
Draw graffiti 5 times on Onishima's back
Fall more than 20 meters off a building
Make 100 civilians jump out of your way
Unlock Gum and Tab
Start the game for the first time