Island Survival

You think that the most important thing would be to find some shelter first. You look around the island for somewhere safe to spend the night. After resting for a bit, you start walking around and exploring the island.

Suddenly you find what looks like a cave, it seems to be a cozy place to sleep. But, if you're worried about the cave, you can also try to build a small campsite with sticks that might also shelter you.

What do you do?