Sid Meier's Pirates! for the PSP is a mix between the PC and Xbox version that were released two and three years earlier, respectively. As a straight port, not much has changed except for three really notable elements:
First, the dancing sequences have been tweaked slightly. Now it is up to the player's twitch/reaction time to get the job done right, as opposed to being able to simply watch the governor's daughter's hand motions and body language;
The second tweak is the addition of being able to physically hunt for treasure. In the Xbox version, the player would find a map, sail to the right spot, and land. Now, similar to the PC version, the player takes four crewman ashore and has to find the red 'X'. All while avoiding booby-traps and vicious jaguars. If the player loses all crew member, it is back to the ship. If the player makes it to the X, then it is time to start digging and rake in the doubloons;
The third change has been made to the sneaking segments. If the player wants to sneak into a port, it is handled in the exact same way; creeping through the streets, slipping past guards, hiding behind fences, etc. However, the player now moves in a grid, as opposed to being able to move a bit more freely. This does not change gameplay, but it is possible to accidentally step into a guard's line of sight because the player cannot stop moving forward until the character reaches the middle of the next tile;
Next to the original game content, the PSP version adds bonus treasure missions, with more plunder and new locations. The game has also been tweaked for widescreen display. Multiplayer is supported for up to four players, through Wi-Fi, Ad Hoc.