Instructions
Defeat the first 15 colossi found scattered throughout the world map.
Journey to sector F5. Skirt the edge of the mountains until you find a path heading southeast. Follow this path to the other side. Approach the two giant stone pillars, then enter the beam of light by the giant door. Reflect the light back to its source using your sword. This unlocks a pair of doors. Enter them.
Ascend the staircase and follow the path. Jump from platform to platform. One jump ends poorly, and you're forced to cling to a wall. Climb the wall all the way to the top to reach the 16th colossus.
Run through the field, remaining close to cover. The 16th colossus periodically shoots beams of energy at you. You must get behind stones and drop into holes and tunnels to protect yourself. Plot your route with this in mind. The most direct route gets you killed.
Go to the colossus's back and stab the trigger. He'll try to swat you. Jump onto his hand for a free ride. He'll eventually move his arm back up. Run along it until you reach his fur. Proceed up the arm until you reach the glowing armband. Do not touch it or you will be electrocuted.
Stab the trigger just beneath the armband. He'll reach his other hand over to swat at you. Jump onto that hand and then stab it. In response, the colossus brings his hand up to his face. Equip your bow and shoot his left shoulder. He'll move his hand closer to his shoulder. Jump onto it.
Climb up his neck and onto his head. Here, you'll find his weak spot. Strike it with your sword to beat the game.