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.

In the style of games made the 8-bit generation of game consoles & computers, or sometimes authentically created to run on original hardware. Common 8-Bit consoles include the Nintendo Entertainment System, Sega Master System, and the Commodore 64

Focused on imparting a skill, lesson, or piece of information to its player that would be helpful to them in other aspects of life, such as a faster typing ability or knowledge about a period in history.

Pretty sure everything is indie on itch.io but just in case you want something extra indie.