A new co-op mission called The NeuroGen Incident is now available as a free download for Interstellar Marines, their work-in-progress, sci-fi first-person shooter. There are details on the official website, and the early access game is on sale for 25% off over the next few days to celebrate the release. "We promised our players tactical cooperative gameplay, and this is our first step towards fully delivering on that promise," explains creative director Kim Haar Jørgensen. "The team has been laser-focused on delivering an exceptional update that meets the highest expectations of the Interstellar Marines community." Here's word on the mission: "The NeuroGen Incident immediately thrusts the player and up to three friends into a pivotal event in the Interstellar Marines universe. The mission ties directly into the storyline of the game and helps to create the foundations for the upcoming single player and coop campaigns."