Walk right once you reach the top and you will come upon a camp filled with characters. Don't enter the area yet. Observe the character up high and the platform just to the left of the one he is standing on. You should be able to see two ropes there with traps on the end.
Once you get beneath the trap platform, the left trap will come swinging towards you. You must move immediately left once you see him going for the rope. You will be safe if you line up with the left edge of the trap platform. Immediately after the first misses you, however, the next will swing from the right, so you need to quickly head right as soon as possible once the first trap goes past.
This is a tricky section to do first time without practice
You can then climb the rope on the left and use the platforms to cross the gap. You will come to a log that you should immediately push into the water. Jump on and again to the rock to the right as quickly as possible – the spider is back and chasing you. Jump from the rock to the next log and climb back onto dry land. Run to the right and stand on the right edge of the log ahead. It will act as a seesaw once the spider steps on the left hand side.
That will raise your end, allowing you to jump to the ledge on the right. Quickly run right and snap the stick next to the boulder. Run back left and shelter in the corner of the dip in the terrain. This will allow the rock to take out the spider and miss you.
Shelter here to avoid the rock and spider.
Move right and jump the gap. Soon you will slide down a slope and find a spike pit guarded by two characters. The spider will come crashing down after you, but it has lost most of its threat. Indeed, the poor critter only has one leg left. Approach it, convincing it to strike at you. Dodge the attack and use the action button to pull off its one remaining leg. With that done, you can climb over the corpse and roll it into the spike pit. Use the body as a platform to reach the next section.