Here is the full list of all 43 Mr. Bree+ achievements.
Get all other achievements
Complete all levels in all game modes
Beat 40 levels in hardcore mode
Beat 20 levels in hardcore mode
Beat 5 levels in hardcore mode
Beat level 24 in less than 29 seconds
Watch the credits cutscene to the end
Skip the last cutscene
Start a level in hardcore mode
Beat all levels without dying
Defeat the slaughterhouse boss
Get 75% of all achievements
Press the red button!
Collect all bad memories
Defeat the forest boss
Beat 40 levels without dying
Beat 40 levels
Collect 20 bad memories
Beat your best time 20 times
Get Double Jump
Perform your first double jump
Get 50% of all achievements
Die 100 Times
Get Wall Jump
Beat 20 levels without dying
Beat 20 levels
Die 10 times in the same level
Beat your best time 10 times
Die 50 Times
Beat the tenth level
Get Run
Collect 5 bad memories
Stay still for a while
Die on the first level
Beat 5 levels without dying
Beat 5 levels
Get Crouch
Quit a level
Die 5 times in the same level
Enter the first slaughterhouse level
Collect the first bad memory
Die 1 time
Get Jump