Here is the full list of all 35 Mushroom 11 achievements.
Beat Chapter 5 Boss
100% Cleared in Chapter 4
Chapter 4 Strand Discovered
Chapter 3 Strand Discovered
The Journey is Complete
A Complete No Death Mine-Cart Run
100% Cleared in Chapter 3
100% Cleared in Chapter 2
Complete Chapter 2 In a Single No Death Run
Beat Chapter 4 Boss
100% Cleared in Chapter 1
Beat Chapter 3 Boss
Complete Chapter 1 In a Single No Death Run
Chapter 2 Strand Discovered
Beat Chapter 2 Boss
Chapter 1 Strand Discovered
Beat Chapter 1 Boss
Beat Chapter 6 Boss
Beat Chapter 7 Boss
Chapter 5 Strand Discovered
Chapter 6 Strand Discovered
Chapter 7 Strand Discovered
100% Cleared in Chapter 5
100% Cleared in Chapter 6
100% Cleared in Chapter 7
Complete Chapter 3 In a Single No Death Run
Complete Chapter 4 In a Single No Death Run
Complete Chapter 5 In a Single No Death Run
Complete Chapter 6 In a Single No Death Run
Complete Chapter 7 In a Single No Death Run
Finish Any Chapter Without Killing Boss
Made it through the Eternal Ring of Fire
Nowhere To Go From Here.
Rise Up and You Shall Reach The Top
Extreme Rocket Maneuver Skills