A 2D platformer is a type of video game that involves navigating a character through a series of levels or stages by jumping and running on various platforms, while avoiding obstacles and enemies. The game is viewed from a side-scrolling perspective, with the player's character typically moving from left to right across the screen.

The levels in a 2D platformer are usually designed with a variety of obstacles, such as pits, spikes, and traps, that the player must overcome using their character's jumping and movement abilities. In addition to platforming challenges, players often face enemies that must be defeated in order to progress, using various weapons or special abilities.

2D platformers often include power-ups and collectibles that enhance the player's abilities or unlock new areas of the game. These can include health boosts, temporary invincibility, or extra lives. Some 2D platformers also incorporate puzzle-solving elements, requiring the player to use their wits to progress through certain sections of the game.

Overall, 2D platformers provide a fun and challenging gameplay experience that requires both skill and strategy to succeed.