Wow, this really needs more attention, it's so good! I loved pretty much everything in it: the pixel art, music, sound effects, menus, color scheme, etc.
The only thing I missed, as pointed out by some, is something like an infinite mode (with a timer that increases gradually less for each time a correct deliver is made) or having the story mode getting more and more difficult as the days in-game passes (expanding recipes, clients, and potion complexity, rather than starting with everything available from the get-go).
Great job!