Subway Surfers is a popular endless runner mobile game co-developed by Kiloo and SYBO Games, a private company based in Denmark. The game was released in 2012 and quickly gained worldwide recognition due to its simple mechanics and engaging visuals. Players control a character running along train tracks, dodging obstacles and collecting coins, power-ups, and keys. The player must avoid getting caught by the inspector and his dog, which adds to the fast-paced excitement. What set Subway Surfers apart from other endless runners at the time was its colorful, cartoony art style, and smooth animations. The game also regularly updates with new 'World Tour' themes based on real cities, keeping it fresh for long-time players.

Subway Surfers became the first mobile game to cross 1 billion downloads on the Google Play Store in March 2018. This milestone underscored the game's enduring popularity in the crowded mobile gaming market. The game continues to thrive, reaching even more impressive numbers, crossing 2.5 billion downloads in 2022. Part of its appeal lies in its accessibility, as it is free-to-play with in-app purchases. Players can buy keys, characters, and special boards to customize their experience. The game's social aspect, including leaderboards and events, also keeps users engaged. Subway Surfers' success can be attributed to its replayability, simple yet challenging mechanics, and consistent updates that introduce new features and content.