Continuity mistake: When Jack uses the cannon to propel himself back to the Pearl and everybody runs up the stairs, Will is holding a pistol and his hands are free, however in the next shot he's still chained.
Continuity mistake: Near the end of the film, during the close haul battle with the Endeavour, the East India Trading Co flag on the back of the Endeavour changes during the scene from initially being blue with white letters into white with black letters. This is first noticeable during the last overhead shot of the ships before everyone yells "fire!"
Answer: He agreed to do a job in exchange for eternal life, with a few limitations. If he refused to do that job he'd be cursed until he fulfilled his duties, but that doesn't excuse him from the details of the previous enchantment. He didn't simply choose not to walk on land, he couldn't.
Phixius ★