This prototype is around the experience of being the owner of a magic potion shop. By mixing ingredients, you can create magic potions that can be sold to shop clients. The gold earned is then used to buy better ingredients, repeating the process.
By directly controlling the character, the player can pick ingredients from jars and add them to a big mixing pot. When the pot is mixed, certain ingredients combine and produce new ingredients with magical properties—for example, health, force, stamina, etc.
Without making new combinations, the price of the potion created will be the same as the price of the ingredients used. But when magical combinations are found, the potion will sell for a higher price. With the extra gold, the player can buy more expensive items and move to the upper tiers of potions.
The price of the potion could vary according to supply and demand, adding an extra layer of complexity. Other approaches to the theme could be around the player picking up the ingredients on the forest or having to discover the effects of the potions by using it on animals and other characters.
The problem with this prototype is that the mechanic used to find combinations of ingredients that yield magic potions was not fun as it sounded it would be. Time to go to the next one.