Where are the Indiana Jones and the Great Circle keys? Some are a lot better hidden than others, and finding them will reward you with access to new locations, bundles of money, and ability-unlocking books. They're well worth seeking out, so here's a full list of the lot.
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Indiana Jones and the Great Circle A Game of Wits Mak-Yek puzzle solution
Indiana Jones and the Great Circle Fountain of Confession puzzle solution
Pay $100 for Indiana Jones and the Great Circle early access, get worse graphics