Here is the full list of all 24 AVICII Invector achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Get an "S+ Rank" on Easy
Get an "A Rank" on 5 levels
Get 50% Perfects on any song
Land 10 Perfects in a row
Hit all gates in a free-fly segment
Complete a song on any difficulty in single player
Get 25% Perfects on any song
Land 5 Perfects in a row
Complete a song on any difficulty in split screen
Get 100% note completion on Easy
Get 100% note completion on Medium
Boost without missing anything on Hard difficulty
Get an "A Rank" on 10 levels
Get an "S Rank" on 5 levels
Get an "S+ Rank" on Medium
Get 100% note completion on Hard
Get a total score of 250 000 across all tracks and difficulties
Complete all levels
Land 15 Perfects in a row
Get 75% Perfects on any song
Get an "A Rank" on 20 levels
Get an "S Rank" on 10 levels
Get an "S+ Rank" on Hard
Get a total score of 1 000 000 across all tracks and difficulties