Here is the full list of all 11 Boltzmann Brain achievements.
Break sand block for the first time.
Start story mode.
Play versus game with 4 players.
Hit The Robot with The Myach.
Complete story mode.
Complete 4/8 chapters.
Break 100 sand blocks.
Enter The Portal for the first time.
Press The Button for the first time.
Press 50 Buttons.
Complete level from trailer.