Pirates of the Caribbean: At World's End

.According to StBacchus' Guide:
You can play Duels with 2 players facing each other. But dueling and the dueling stages, respectively, first need to be unlocked by completing challenges in Challenge Mode.

Stage | Opponent | How to Unlock
------------+-------------+-------------------------------
Tortuga | Villanueva | Combo Challenge on Tortuga
Isla Cruces | Norrington | Combo Challenge on Isla Cruces
Singapore | Lian & Park | Loot Challenge on Singapore
Sea Battle | Sao Feng | Loot Challenge on Sea Battle
Maelstrom | Davy Jones | Combo Challenge on Maelstrom

(from http://www.gamefaqs.com/console/wii/file/937751/49583)