Atelier Rorona: The Alchemist of Arland

A travelling alchemist visits the kingdom and shows its residents how to use the abandoned technological relics of nearby ruins. This begins a new era of prosperity within the kingdom. As a reward, the king allows the alchemist to open an alchemy workshop within the kingdom. A great many years later, the workshop is all but forgotten. One day, the workshop receives an ultimatum from the king: prove its usefulness in three years time or face closure. (mobygames)