Albert is a young sorcerer apprentice on a wizard academy, alongside his sister Lilian. On his birthday, he goes to her room to find the magic mirror smashed, and no sign of Lily anywhere. After gathering some clues he starts to unveil a conspiracy: an evil opponent plans to take over the universe with the help of the Key of Eiron, a powerful artifact. He must go in a dangerous journey to save his sister and the world.
Elementals: The Magic Key combines elements of three genres: adventure, hidden object and turn-based strategy games. Most of the time, the game plays like a normal point-and-click adventure, where the player has to explore locations presented as first-person static screens, navigating from room to room by clicking on exit hotspots, usually positioned on logical places like doors and other openings. Objects can be found scattered around, and stored in the inventory for use later when solving puzzles. In some locations, the hidden object gameplay section starts after completing an adventure puzzle, where the objective is to collect all the items listed on a scroll at the top-left side of the screen. Felly, Albert's familiar, acts as the hint button, showing the position of one of the required objects but taking some time afterwards to recharge.
The inventory objects are shown on slots at the bottom, from where they can be dragged and dropped on appropriate and logical places of the scenery to perform an action or solve a puzzle. The strategy section starts when the main character is attacked by an enemy, bringing up a separate battle screen showing two fields for each player. The goal is to eliminate all the enemy pieces by moving and attacking in turns. Each piece is an elemental, with varying attacking range and power. The fields are grids, and when three identical elementals are lined up on it they can be fused together to become a new, stronger piece. Some puzzles take place on a separate screen, where a mechanism of some sort has to be manipulated directly to solve it.