Thank you for playing the game!
As you might have understood, this is actually an arcade game, and the potion book feels much more natural as a physical copy with the actual controllers. We did play around with an in game potion book though, to make the game feel more coherent when you play it on a keyboard. We would have loved to have both options if there was enough time.
We aimed to push the players to disturb one another in the potion making, which is more obvious with the arcade controllers since the shelf button is huge. A pro tip though: You can still be sneaky and press the "E" or "right shift" button for the other person if you are quick enough. This drives my friends crazy, but it's too much fun not to mess with the other person and it brings out a lot of laughter!
We are all glad you enjoyed the game!
/Kiwi Backman, producer of Potion Panic!