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.

A popular game from 2013 where you must tap a bird to dodge pipes. Many clones & fangames were made because of the original game's success. 

Games where the primary goal is keeping the player character alive under harsh circumstances such as dwindling resources or a hostile environment.