Many of them have fun ways to get around

Sandboxes are perfect for super-powered characters such as Cole MacGrath. If the way to get around is fun in and of itself, players may not even bother with the main missions. The "Infamous" games allow players to leap over tall buildings, grind on powerlines and hover. This leads to many races and challenges that take full advantage of Cole's powers. Similarly, web-swinging in Insomniac's "Spider-Man" not only feels cathartic, it also takes a degree of skill to pull off without error.