The author of the new action roguelike dungeon crawler kind of darwen mayham game Gorynlich was so kind to inform us his game. It comes with this funny trailer (and some great programmer's art :p ):
The code is licensed under the LGPL, while the assets are only freeware right now. But the author seems to be open to look into replacing the assets with Creative Commons licensed ones if someone is interested in doing so.
Gorynlich is done by the same author as the ASCII game Goblin Hack by the way.
Another nice game starting with G, is the awesome remake of the oldie Megalomania, appropriately called Gigalomania!
The author is still looking for improved art asset contributions, but the game itself is already quite playable (even on mobile devices and a bunch of other rare systems!). Also check out the other two cool games by the same developer: Erebus RPG and Conquests (a Civ like game).