The brief
Strongbow needed a small, branded game for its GOAT promotion that strangers could walk up to and play with no explanation. The idea was simple enough to describe. Making it hold up on a public stand for the whole promotion, with people of every level of patience prodding at it, was the part that needed working out.
What I worked out and built
This was a smaller job than the Coca-Cola machine, and I'd describe it that way: a simple promotional game, built carefully. I wrote the software; there was no hardware work.
It ran on a landscape touchscreen as a browser game, using the brand's real graphics. Players saw a 3 by 4 grid and had three attempts to find the gold coin, with a prize for finding it.
Most of the thought went into how people actually behave at a touchscreen. Some walk off halfway through a game. Some tap the wrong square by accident, and some hit the screen over and over before it has had a chance to respond. I handled that mostly through input validation.
Constraints
The unit stood in a public place and was played by strangers. An attendant handled restarts and abandoned sessions, and gave out the prizes, so the software wasn't entirely on its own. It still had to behave properly for every player the attendant wasn't watching closely.
Outcome
It went fine. The few issues were players walking off mid-game and leaving a session hanging until it timed out. The brand ambassador on the stand reset those as they came up.