You are an ape. Corrupted by snakes. On Mars.

-Your snake overlords have ordered you to hunt the rogue martian thru your dying city. SNAKE H.E.D. technology will chart the martian's dangerous path. Follow him. 

-As always, use your mind snake constructs to manipulate the world around you.

-Visit Tars Tarkas Hospital, but beware the hateful eyeballs that infest the bodies there.

-At Killraven Park, kick a ball, swing on swings, find the secret sewer entrance.

-Collect mind keys. The candles at Saint Hubert George are an involved riddle.

-Never gonna stop. 

-The dogs might not like it if you play the arcade game at Ignivomus Bar without their okay.