Ow, yeah... I see the confusion here...
The theme of the Jam is Astral and that's announced before the Jam starts, but that theme is optional, purely inspirational, not required.
And then the moment the Jam starts they announce the limitation, for this jam is:
Base your game off of a myth or legend
That was the actual theme for the Jam
Still, great game, I tried previous games you did and I can see you're improving, keep going! :D