Here is the full list of all 27 Critical Mass achievements.
Use A Fusion Pulse Above 90% Critical Mass On Normal Difficulty Or Higher
Complete Classic Mode On Normal Difficulty
Survive At 80% Critical Mass For 10 Seconds In Survival Mode
Complete Classic Mode On Casual Difficulty
Spin The Mass 300 Times In 10 Seconds
Create A 13x Combo In Any Game Mode
Beat Your Personal Best Score In Classic Mode
Get An Epic Performance Rating In Any Game Mode
Reach Rank 1 In The Overall Leaderboard
Complete classic Mode On Normal Difficulty In Under 20 Minutes
5 Combos Within 10 Seconds In Rush Mode
Unlock All Achievements
Play For 100 Hours
Complete Classic Mode On Expert Difficulty
Complete Classic Mode On Expert Difficulty In Under 20 Minutes
Complete Classic Mode On Normal Difficulty Or Higher Without Using Rotation
Complete Classic Mode On Normal Difficulty Using Both Normal & Reversed Controls
Complete Classic Mode On Normal Difficulty Or Higher Without Using Timewarp & Fusion Pulse
Complete Classic Mode On Casual, Normal & Expert
Reach Rank 1 In Classic Mode On Normal Difficulty Or Higher
Average Action's Per Minute 80+ In Rush Mode
Reach Rank 1 In Rush Mode
Build A 16x Combo In Meditation Mode
Finish Meditation Mode With A Score Of Zero
Reach Rank 1 In Meditation Mode
Survive For 5 Minutes In Survival Mode
Reach Rank 1 In Survival Mode