Here is the full list of all 39 Pentagonal Saloon achievements.
Fece the fist
Catch your candies
Eat your lollipop
Collect your sugars
Get wet
Solve the puzzle
Get bitten by spider
Eat your chocolate
Get the flamethrower
Free the ghost
Let the sugars flaw
Locate the goblet
Get all confirmations from the screens
Collect the square card
Solve the geometrical puzzles
Collect the triangle card
Collect the circle card
Open the geometrical doors
Solve the goblet puzzle
Collect a note
Solve the puzzle at room-4
Make all playing-cards visible
Collect a coin
Solve the light games
Solve the puzzle at room-3