itch.io

Uses two-dimensional "sprites", 2D images created and used on a flat plane, as opposed to the three-dimensional models or environments found in 3D games.

Projects that don't use any digital rights management.

Sprites are generally 2D images used in games to represent objects. They can be animated or static, and come in different styles like isometric or top-down.

Resources for building and relating to User Interfaces, how the user interacts with your program