Wikipedia
Shadowgrounds is a top-down shooter for Microsoft Windows, Linux and Mac OS X, developed by Frozenbyte. The game takes place on a space colony on Ganymede which is being attacked by aliens. It was released for Windows on November 11, 2005 in stores in Finland and Germany, and in Spring 2006 in the rest of Europe and North America.
As well as being available through retail stores, the game began being distributed on Valve Corporation's Steam on May 8, 2006. The game was also available on Gametap as of January 31, 2008 until it's closre, and is on Good Old Games as of March 3, 2011. The game was later ported by IGIOS and published to Linux by Linux Game Publishing, with the Linux version being released on September 16, 2009. It was made available on Desura on April 10, 2011.
A sequel, Shadowgrounds: Survivor, was released in 2007 and focuses on three separate characters trying to survive the alien onslaught shown in the first game. Both games were later released together along with two other Frozenbyte titles, Trine and Splot, to form the third Humble Indie Bundle. The Humble Frozenbyte Bundle games were also offered as incentives in the later Humble Frozen Synapse Bundle.
Shadowgrounds is the name of a shoot 'em up video game series for Microsoft Windows, Mac OS X, and Linux developed by Frozenbyte. The games are fast-paced top-down shooters reminiscent of the Alien Breed series and present anachronistic concepts with modern resources. The plot of a monster attack on a space colony exists only as a thin justification for the action, monsters are plentiful and weapons large.