Oh also I think if you could upgrade things that would be great! See it would be really interesting if you could survive with friends but then you could build weapons on the raft to attack other rafts for example. Also I do think the shark thing would work better if you had like perhaps sometimes more than one! Then you could feed your captures to the sharks haha. If there were different amount of sharks also it would be less predictable and perhaps if you fed the shark it could leave you alone for longer for example.