Gemstone Keeper is a twin stick shooter where avid explorers go down into the Cistershire Caverns, a large, dangerous and mysterious set of caves and caverns that are filled with vast amounts of rare and valuable gemstones. This game combines the quick and reactionary feel of a shooter with the exploration and decision making of classic roguelikes. Using an ASCII art aesthetic in its purest form, all visual assets are produced from a single text font file, software rendering and visual effects. The weapon and bullet system is fully interchangeable, over 150 gemstones to collect, several creatures and bosses, different game modes and a soundtrack that echoes through the open spaces in-between the rocky walls. Gemstone Keeper is the shooter that is both fun and eerie.