I have 3 ideas
A Backpack for have more inventory
Uprades for the foundation's and the floor's etc etc... Ej: Uprade to Iron or Wood Reforced
Modes of game Ej: Hardcore (the actual mode), Normal (The shark attacks less and does less damage), Easy (More resources and the shark almost does not attack and takes very little life), Peaceful (No shark), Creative (No shark, You have everything)
Thanks for your attention ^_^ !!