ISOTX was a Dutch independent video game developer founded by Vincent van Geel and Byron Rupp in 2005. In 2014 Vincent van Geel left the company. The company continued on, yet dissolved in 2016.
Their first release was the MidEast Crisis mod for C&C Generals. This was followed by Iron Grip: The Oppression, a mod for Half-Life 2. Since Iron Grip: The Oppression, nearly all ISOTX games have been set in the Iron Grip Universe; a dieselpunk alternative reality setting.
In 2008 ISOTX released their first commercial game, Iron Grip: Warlord, which received somewhat mixed reviews. IGN only gave the game 4.5/10, but other smaller websites gave more positive reviews. The gameplay in Iron Grip: Warlord offered a mix of first person shooter and tower defense gameplay. While defending against waves of attacking enemies, players had to hunt down enemy officers to reduce enemy morale and win the battle. In 2012, ISOTX released the Scorched Earth DLC for Iron Grip: Warlord on Steam, which added new weapons, enemies, and a deathmatch game mode
The next game released by ISOTX was the free-to-play strategy MMO Iron Grip: Lords of Atelia, which would later be renamed to Iron Grip: Lords of War.
In 2011, ISOTX launched the open beta of their second free-to-play strategy MMO, Iron Grip: Marauders, which featured 3D turn-based battles using the Unity game engine. The game was released through Steam, an online distributor, as part of their Free to Play catalog on September 30, 2011. Iron Grip: Marauders became available on Amazon.com through their Games Connect feature in 2012. Marauders has received a number of significant updates, often changing gameplay or other major features. It received a notable visual upgrade on March 18, 2011. To highlight the 3D capabilities of the game, the developers changed the view from an isometric camera to a perspective camera and added a zoom function to allow players to look more closely at units and structures. The developers also upgraded the internal Unity engine from 2.7 to 3.0, with plans to make use of the new engine's capabilities to add lighting effects and more detailed terrain maps in later patches. The "Boss Smash Patch" released in May 2011 included a day and night cycle, more units, avatar customization, and bosses which randomly attack players. Other changes include a base building system where players could place structures and units to produce income and defend the base (this was later removed), the introduction of a smuggling system, and more recently an assault system where players could pick units to go on an automated 10‑minute battle. In April 2012, ISOTX partnered with QINQO, meaning that people in Belgium and the Netherlands could buy in-game currency from shops in the form of prepaid QINQO cards.
In March 2013 ISOTX revealed their new project, a free online multiplayer game, March of War. It's going to be a F2P strategic, turn-based episodic multiplayer world war online game for PC, Mac and iOS/Android. March of War takes places in an alternate dieselpunk influenced 1940 world, where democratically elected players lead six warring factions through the turn-based episodic struggle for world domination. It's the world's first episodic free-to-play game based on the TV series model. The game promises over 80 units and 60 maps with four gameplay modes. Every month a new episode is released bringing a number of new features to the game.