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)

Pixel Art refers to the charming, simplistic, retro/renaissance style of very-low-resolution graphics, such as from the 1977-1995 Atari, GameBoy, & Super Nintendo (SNES) eras.

PNG, or Portable Network Graphics is a common image file format that is lossless, can contain an transparency channel, and compressed. An ideal format for distributing static assets without any loss in quality.