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