Ay Island Windows, Mac game

Since Nelson and Billy were able to dream, they both wanted to be at sea and become true adventurers. Of these dreams, their biggest of all was to discover and explore an unknown island. One day, when they were on the sea, this dream came true.
They discovered an island! Certainly... apparently someone else.
And so, how they expected it, it was rather different.
Crazy natives, mystical curses, pushy salesmen, voodoo, pirates, treasures and much more. Additionally there seems to buried something powerful.
An incredibly powerful artifact, that had been forged by the first gods by themselves. A story is going about that the power of the artifact, can make you the strongest and mightiest human being in less than one second.
You could destroy the whole world with just one thought... and this revelation has been discovered by the most horrible pirate of the sea. His name is DeMorris. He wants to use this power, to destroy anyone, who wants to get in his way. The adventure is going to begin...