Most of the fun in the game comes from testing each possible ingredient and trying to find the right ones. This, combined with the pixel art, music, and sound effects that play when you select an ingredient, creates a very satisfying atmosphere that made me feel like a true alchemist.
One thing I didn't like was that you only get points when you reach the exact stat value required by the client. This limits the possible correct answers to just one and creates moments where you come very close in all categories but still receive a negative score.
I think you should focus on the trial-and-error aspect of the gameplay: randomize the ingredients each round and make the score depend on how close the player gets to the client's request.
Overall, this is a very polished game with a great variety of content for a game jam. The difficulty progression is excellent. I especially liked how you portrayed the customers in a hurry; it creates a sense of urgency that really pulls the player's attention back.