Hi there! LÖVE is an awesome framework you can use to make 2D games in Lua. It's free, open-source, and works on Windows, Mac OS X, Linux, Android and iOS.
OGRE (Object-Oriented Graphics Rendering Engine) is a scene-oriented, flexible 3D engine written in C++ designed to make it easier and more intuitive for developers to produce applications utilizing hardware-accelerated 3D graphics.
Pygame is a set of Python modules designed for writing video games. Pygame adds functionality on top of the excellent SDL library. This allows you to create fully featured games and multimedia programs in the python language.
Allegro 4 and Allegro 5 are cross-platform, libraries mainly aimed at video game and multimedia programming. They handle common, low-level tasks such as creating windows, accepting user input, loading data, drawing images, playing sounds, etc.
Amulet is a Lua-based toolkit for experimenting with interactive graphics and audio. It provides a cross-platform API for drawing graphics, playing audio and responding to user input, and a command-line interpreter for running Amulet scripts.
HGE is an easy to use yet powerful hardware accelerated 2D game engine. It is a full featured middleware for all who want to develop commercial quality 2D games rapidly and easily. It covers all imaginable 2D game genres: you could create everything from a simple puzzle to...
DragonRuby Game Toolkit is a professional grade 2D game engine. It's tiny (~3.5MB), fast, and cross-platform (including consoles and mobile).