Geometry Dash is a popular rhythm-based platformer game developed by Robert Topala, released in 2013. Players control a square icon that automatically moves forward, and the main objective is to navigate it through various levels filled with obstacles. The game is known for its challenging gameplay, where players must jump, flip gravity, and perform other actions in perfect sync with the geometry dash level's background music to avoid obstacles and reach the end.

The game offers:

1. Multiple Levels: Each level has its own soundtrack and obstacle pattern. Some levels are created by the developer, while others come from a large community of player-created levels.
2. Customizable Icons: Players can unlock and customize their icon with different shapes and colors.
3. Difficulty Levels: Levels range in difficulty from "Easy" to "Demon" for extremely challenging ones.
4. Practice Mode: Allows players to practice parts of a level with checkpoints, making it easier to learn challenging sections.
5. User-Created Levels: The game has a robust level editor, allowing users to create and share levels with the community.

The popularity of Geometry Dash also comes from its vibrant community and the wide range of player-created levels, which keeps the gameplay fresh and challenging.