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