A way of building game levels from small repeated squares, like floor tiles: ground, wall, platform, water.
Instead of drawing a whole level as one big picture, the screen is divided into a grid of equal squares, and each square holds one tile from a small set: grass, dirt, stone, platform. With only twenty tiles you can build hundreds of different levels. The game knows from the tile type whether the player stands on it or passes through it.
This makes levels quick to build and change, and keeps the game light on devices, which is why platformers and mazes rely on it. In Fanann you start from the 2D game templates, such as the platformer and the maze, and ask in plain words to add a platform, widen a gap or make the level longer. Practical tip: draw your first level on squared paper before anything else. One square per tile, and mark where the player starts and where the goal is. The paper shows you a level is too long or dull before you build it.