Here is the full list of all 19 AudioSurf achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Fill all columns within 15 seconds. No greys. No matches.
Using Ninja Mono, earn Stealth. 11 min minimum.
Finish Clean, Gold before finish, hit last block, elite only.
Turn 21 blocks red with a single paint.
Make a candy stripe.
Beat a friend's score less than 15 min. after they earn it.
Dethrone a friend from a global scoreboard.
Using Ninja Mono, earn Stealth. 7 min minimum.
Stealth and collect every color block. 3 min minimum.
30000 points per minute. 3 minute minimum.
Earn triple a gold medal requirement. 2 min minimum.
Earn Gold without overfilling. 2 min minimum.
Using Ninja Mono, earn Stealth. 3 min minimum.
Earn Clean Finish and Gold 3 times in a row.
10000 points per minute. 3 minute minimum.
Collect matches in 4 colors simultaneously.
Collect a chain reaction of 7 white blocks.
Score 17000 points in a single match.
Collect a match of 24 blocks.