day and night,(and if you dont sleep you die because you are to long awake), torches/oil lamp and a bed to skip the night, diffrent sorts of fish (such as raw salmon), spikes to add on the edge of the foundation to defend the shark, achievements, make that you instantly die by falling of the edge of the world, make powersource like a dynamo to make elektricity or a peddle wheel to make things automaticaly, the shark must despawn after 5 min when you killed the shark (and you didn't took the meat of it), bow and arrows to shoot the shark from a distance, animals like birds/fish to breed, rotten fish in a barrel where maggots are, with maggots you can catch diffrent fish, all your tools must have durability, bucket where can fill up ten cans. already I love the game very much
PS:sorry for the bad english
(i like the dynamo-idea the most)
you don't have to edit all of this in the game
Good luck!