https://store.steampowered.com/app/3073040/Seoul_Station/

This game is a “Find the Difference” game set in the Korean subway system.
At the start, you will board the normal 0th train. Once you move to the 1st train, the real adventure begins. From the 1st train onward, you need to find differences from the 0th train.
Differences may include changes in the subway’s structure, internal advertisements, or even variations in your character’s movements. Various anomalies, ranging from subtle to significant, are ready to challenge you.