Solar Struggle

Solar Struggle is an Ultimate Doom, limit-removing (Complevel 3) community project. Each map was given a name first and then participants were invited to make a level based of it. The first 3 episodes are comparatively easy and short, and the 4th is ramping difficulty up quite a bit. The maps are balanced for pistol-start primarily.

You are an unnamed convict imprisoned on Titan. When demon invasion threatens the Solar System, he gets a chance to escape. But there's a horde of demons between you and freedom.