List of Free code 2D Game
Simple arcade style basketball game in 2d.
Final year university project looking into using machine learning techniques in a game environment. The game takes Lemming's as inspiration, with the agents able to learn optimum paths through the 2D environment using reinforcement learning.
derp octo nemesis
Experimental iOS 2D game stuff, formerly Aposelene.
Simple Obj C 2D top down game engine (Pokemon style).
An example 2d game engine built on GLKit.
A demo iOS app showing how to use the new SpriteKit API to build a simple 2D fighter plane game.
SpriteKit 2D game tutorial.
Retro style Cocos 2D game for iOS and the Mac.
A framework for the creation of 2D games.
Another version of the game Orfeus for iOS devices. The game uses the Cocos 2D framework.
A 2D adventure game engine.
Tabby2D, a lightweight 2D game engine. well, for iOS only. Still in early alpha phase...
2D game engine built on iOS 5's GLKit.
Wyrm is a 2D MOG (Multiplayer Online Game ) based on SFML.