Flare (Free Libre Action Roleplaying Engine) is a simple game engine built to handle a very specific kind of game: single-player 2D action RPGs. Flare is not a reimplementation of an existing game or engine. It is a tribute to and exploration of the action RPG genre.
Flare is currently in development. Though it is meant to be a game engine which can be used to create more games, it is turning out to be a full game in itself. Check out gameplay video:
Flare Linux builds are not available on the official page at the moment. However, you can easily compile it from source code. The good news is that Ubuntu 12.04 has latest version of the game in official repositories, so just hit Software Center to install the game.
If you want to try out the 12.04 Deb packages in older Ubuntu Releases (not tested):