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.

Resources relating to or for building Graphical User Interfaces (Commonly called GUIs)

A game in which the player is not constrained to achieving specific goals and has a large degree of freedom to explore, interact with, or modify the game environment 

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