There is an unwinnable state that can be reached by beating the game and loading a savegame file from the start of the game.

There will be no floppy disk in the flashback, making you unable to leave the island, softlocking you.

If you hit "New Game" instead, the floppy disk is there. I do not know what the exact conditions are to trigger this bug, but "beating the game and loading from the main menu" does the trick. Loading again from a buggy state will still leave you in the buggy state.