Here is the full list of all 19 VVVVVV achievements.
Complete the game in flip mode (any number of trinkets)
Complete the game in no death mode.
Obtain a V Rank in this Time Trial.
Complete the game with less than 500 deaths.
Complete the game with less than 250 deaths.
Complete the game with less than 100 deaths.
Complete the game with less than 50 deaths.
Last 1 minute on the Super Gravitron.
Last 30 seconds on the Super Gravitron.
Last 20 seconds on the Super Gravitron.
Last 15 seconds on the Super Gravitron.
Last 10 seconds on the Super Gravitron.
Last 5 seconds on the Super Gravitron.
Complete the game (any number of trinkets)