Prompt: Sketch a first-person shooter game storyboard: A group of space marines are sent to investigate strange events at a remote research facility on Mars. Once they arrive, they find themselves at the mercy of genetically altered killing machines. Players assume the role of space marines and traverse each level of an incredibly large military base's labyrinth-like interior space in search of an exit or to defeat hordes of genetically enhanced undead humans and invading alien monsters. Make it simple, black and white, suitable for a 1920×1080 display.