The idea for this game was born during a Twitch stream. 

The concept is simple: you buy products for a low price and sell them for a higher price, earning more and more profit.
It's a matter of slight trial and error and also some logical thinking about what a realistic price is.

Early testing revealed that the game is fun and really hooks players quickly. It's easy to understand and actions have very direct feedback.
The reception was so surprisingly good that the game is being further developed with additional features, such as upgrades,  suppliers apart from buyers and stall improvements.