Steel Storm is an independent video game series developed by Kot-in-Action Creative Artel using the free software DarkPlaces engine that were released for Microsoft Windows, Mac OS X, and Linux platforms. The game was added to the Humble Indie Bundle 3 on August 1, 2011.The games are divided into two episodes, with Episode One being available at no charge and Episode Two (titled as Steel Storm: Burning Retribution) being a commercial product. They are top down arcade shooters where players control a hovercraft while battling presumed extraterrestrial invaders using a variety of different weapons.