Actually, the KQIV ending has many variations depending on what you did previously in the game:
If Alex sends his signet ring to Cassima, or reclaimed it from the pawn shop, it will become the wedding ring. If not, there will be no wedding ring.
Cassima's parents may or may not be at the wedding, depending on if Alex saved them from the Land of the Dead.
Jollo will behave differently at the wedding depending on if Alex befriended him and if Cassima's parents were saved.
The genie and rulers of the island may or may not attend the wedding, depending on if you saved the genie, discovered the stolen treasures and saved Cassima's parents.
The keys to getting the ultimate ending are to send the signet ring to Cassima, befriend Jollo, save Cassima's parents, save the genie, and discover the stolen treasures. Do none of these things to get the worst (successful) ending.