Here is the full list of all 14 64.0 achievements.
The base game contains 10 achievements, and there are 2 DLC packs containing 4 achievements.
Get a score of A+ in all the levels, from 64.1 to 64.5
Complete 64.5 level
Complete 64.2 level
Retry one level 64 times in a row
Survive 64.0 seconds or more in the endless level
Complete 64.4 level
Complete one custom level
Complete 64.3 level
Play one custom level
Complete 64.1 level
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Complete Mind Twister level
Complete the Polkka level
Complete the Superpower level