From StrategyWiki, the video game walkthrough and strategy guide wiki
- You begin this stage in the bottom left corner of a forest. Your goal is to reach the base entrance in the upper right corner atop a cliff. You'll have to get there by firing your grappling hook to various tree limbs and pulling yourself up to new heights. The map on the sign behind your starting location actually gives you a pretty good idea of how the stage is laid out.
- Watch out for soldiers who appear immediately above you. You can leave the sleeping heavy soldier alone, and bypass him completely by pulling yourself up to the branch directly above you. Make your way up to a third branch and run to the right where you will have to shoot down the first electrified barrier. As you do, a fast-grapple item will be parachuting down from the sky. Be sure to hit it with the grappling hook diagonally before it gets too far to retrieve.
- After blowing up the barrier, you'll have to grapple diagonally to the long tree branch on the right. Your grapple will not catch below any spikes, so if you can't seem to grab the branch, move back to the left a bit so that the grapple is catching a clean part of the branch. Then swing over to the right, and you should fly over a set of spikes. As you do, a green gun may be parachuting down. It's worth making a little extra effort to grab it, as it's quite powerful, and can defeat heavy soldiers in two hits. Just be careful because the middle of the stage has no ground, so if you fall through the bottom of the screen, you will lose a life.
- When choosing branches to grapple to, be sure to avoid hitting the beehives. If your grapple hits one of them, they will anger the bees inside, who will come out and form a swarm that chases you around the screen. If this happens, be sure to run away, and hit the swarm with the grapple to chase them away and send them back to the hive.
- After you reach a narrow section around the central tree, you may notice that some of the branches are two slightly different tones. These branches will fall after you have stood on them for a small amount of time. Even if you grapple off before they break, they will still fall. However, shortly after they fall, a new branch will instantly grow back and replace the old one.
- By the time you start to see the breaking branches, you will encounter the gliding mutants that climb the tree trunks and fly through the air. If you can shoot them, you should remove them as quickly as possible before they become a nuisance. If you don't have the opportunity to shoot them, you can still whack them with the grappling hook and scare them off. Alternatively, you can grapple a point diagonally above you and knock them away by swinging in them, a technique you can also use on soldiers. Never try to grapple up to a higher branch before scaring away any mutants that can hit you while you are rising.
- The stage continues much higher up than you need to travel in order to exit the stage. However, as you continue to climb, you will see more items and weapons being parachuted in. If you are a skilled player and not too worried about dealing with enemy soldiers and mutants, you can scour the level to obtain a blue or green gun, and a few high-point medals to boost your score and grant you some extra lives.
- Regardless of how high you travel, don't forgot to keep moving to the right. Your goal is on top of the rightmost cliff. Be aware that you can also grapple through the bottoms of cliff to the surface on top. Once you see the scene depicted to the right, hop on to the cliff, blow up the last electrified barrier, and run to the right to reach the end of the stage. There is no final battle or boss to defeat, simply reaching the sign signifies the end of the stage.