According to lore in the Sol Dimension, Pirates' Island was the build by the long-lost civilization once native to Sky Babylon to be the inhabitants' new home after they were forced to abandon their continent when it fell from the heavens into the ocean's surface.
Pirates' Island was originally ruins left behind by an ancient civilization, but the pirates, under the command of Captain Whisker, established their hideout here, filling the valuable ruins with weaponry of all kinds while remodeling the archaeological relics.
Being the final "regular" level of the game, Pirates' Island features a large number of game gimmicks: trebuchets allows Sonic and Blaze to launch themselves into air while catapults throw rocks along with the player, breaks down obstacles, high-pressure water cannons creates rails for Sonic and Blaze to grind on, large anchors which either acts as a platform or a large weight that can crush the player, fountains that can shoot people into the air, dolphins that can be ridden underwater, and finally timed gates that will close after a certain amount of time has elapsed, thus blocking shortcuts.
The bosses of this stage are Captain Whisker and Johnny. This is a somewhat unique boss fight in the Sonic series as the player faces two opponents at the same time. Whisker can breath fire, launch his fists at the player and create shockwaves when stomping into the ground and Johnny can fire himself as projectile. The two of them can also attack together; Whisker throws Johnny at high speed, thus making Johnny a faster projectile that can bounce off walls and becomes far more unpredictable.
Pirates' Island appears in the Sonic the Hedgehog comic series and its spin-off comics published by Archie Comics as the primary base of the Blackguard Pirates. A giant oil drum is in the center of the Island and this is where the pirates are located, the Kraken lurks in the waters beneath the oil drum. The Island was home to the Sprockets until the pirates arrived and made it hard for them to liver there.