Banished from a magical party, you find yourself marooned on an island...

After I looked up what exactly "castaway" means, I got to the dictionary entry for "cast".
It turns out you can cast so many different things!
I decided to make a minigame each for a few things you can cast. Give the player options, and let them cast away!
For even more theme, the game takes place on an island with the protagonist as a castaway.
 
Cast for fish
 
One obvious thing you can "cast" on an abandoned island is a fishing line. Here, it's a way to get food (needed for each action), and small amounts of other resources.

A dice minigame works as well, but how to get dice on an abandoned island? Catch cube-shaped boxfish, and throw those?

You can throw multiple dice, and a pair of the same symbol will give you a bonus. That's a good way to get more of the Magic resource.

If the player is a magician, they can melt iron and pour it into a suitably shaped hole to create an object.

The holes are dug by mind-controlled worms, steered by a deck of magic cards – that makes this a bit of a puzzle.

If you make more items than fit your inventory, you can—wait for it—cast one away before making a new one!

To get some attention, a castaway should write HELP in large, visible letters. In this case, the letters can be projected on a rock wall by a fire! Should be plenty visible at night.

That determines what knid of shaped you need to cast in iron: the letters H, E, L and P.

And of course, one can cast magic spells! Teleporting would be easy, let's use something to attract attention.

Use your keyboard (only!):

The game saves state to a persistent JSON file, and will continue when re-started.

The location of the file is written to the console.