Hallo,
I have 4 ideas.
1. throwing spears, because running to the shark is often to slow
2. maybe Birds you can cook
3. a multiplayer would be nice, 1 player 1 raft, 2players 2 rafts which are a little bit far away so the one try to go to the other player
4.Difficult, maybe that by easy 0 sharks,normal 1 shark,hard 2 shark which are more aggresive and doing more damage and having a little bit more health (not 3 times stabbing they swim away)
it would be nice if one of them could be done.