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