Here is the full list of all 16 Neon Prism achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Collect 50 medals
Get gold medal on every level.
Finish last level
Use slow 50 times.
Collect 10 medals, bronze or better.
Collect 10 silver and gold medals.
Collect 10 gold medals.
Use slow 15 times.
Use blink 50 times.
Use slow 5 times.
Use blink 15 times.
Use slow.
Use blink 5 times.
Use blink for the first time.
Finish first level
Finish tutorial level