Cool concept. I think the first thing to do would be balance the different pieces against each other. Being in shade helps with water, but puts you in danger of coconuts or crabs because you are not moving. Running around allows you to avoid enemies and find water, but the heat starts to get to you. Currently I think the coconuts are too frequent which means you can't really win by staying in the shade, and the heat is too strong or not enough water items around, so you can't really win that way either. You have a good core here though, nice job.