Every castaway starts adrift at sea on a Raft. Once you find land, you would be lucky to have more than one palm tree to use for resources. You must strategically use what is available to you so you can survive and produce more of these resources in the future. With the help of some friends, you could build a thriving village together. Then, you can travel the seas to other islands and trade valuable goods with other castaways.
You can play Castaways for free right now! Keep in mind the game is currently in Alpha which means it is nowhere near finished, so it can be a bit unstable during updates.