Here is the full list of all 12 Dragon's Lair achievements.
Get the highest possible score (427,469).
Complete the game without dying.
Dirk dies via asphyxiation in the bedroom scene.
Complete the game with the move guide turned off.
Lose your last life in the Drink Me scene... Watch Carefully!
Complete the game on any mode.
Complete the game in Hard mode.
Complete the game on Arcade Mode
Use the shortcut in the Giddy Goons room.
Get off on the elevator on the last floor.
Never make a correct move in a new game.
Play Dragon's Lair on its Anniversary: June 19