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