Here is the full list of all 14 Gizmos: Spooky Adventures achievements.
Game completed!
You've collected all the Bronze medals!
You've collected all the Silver medals!
You've collected all the Gold medals!
You've unlocked 100 cells in a row with no misclicks
You've unlocked 500 cells in a row with no misclicks
You've unlocked 1,000 cells in a row with no misclicks
You've made par in all the puzzles
You've played for five hours
You've played for ten hours
You've played for 20 hours
You solved a puzzle without using the right mouse button
You've solved all the puzzles
You've collected all the rewards