Ideas:
-Different kinds of fish, and maybe different fish replenish different amounts of hunger. (etc, Raw Tuna replenishes more hunger than Raw Mackerel)
-The fishing is way too easy, it's an unlimited food source. Combined with what I said in the first idea, I think there should be a boot you can catch. Catching a boot while fishing is Comedy Gold, my friends. Say like, 75% chance of catching fish, and 25% chance of catching the boot.
-Add the ability to destroy/remove cooking stations, water purifiers, etc. I know you can remove them by hitting the foundation that they're on, but that's wasting a nice piece of foundation.
-Day and Night Cycle, and at night time the shark is more aggressive.-Adding weather would be neat, too.