You should add some Music to make it more peaceful, and also make the players choose which music they want in settings. i recommend adding more items that require scrap. and making the map infinite because some youtubers managed to get to the edge of the map.
Maybe there would be gentle ambiance music when the player is just surviving, but things get more intense if the shark is coming? And if music is added, there should be an option to turn it off. I'd hope the music in the game would be copyright-free and/or royalty-free, because not too many games do that, and it makes live streaming and video recording a pain.
As for the scrap, it seems that the newly-added chests require quite a bit of scrap. So that's useful. Other suggestions have been things like harpoons.