"The game features 18 levels, and has five playable characters. They are:
Mr. Incredible: Used for most of the game, he spans 11 of the levels. While his techniques are the same, his clothes change:
Young Bob Parr (his first two levels, blue suit)
"Keeping Identity Secret" Bob (one level; burning building)
Old Bob Parr (three levels; old blue suit)
New Bob (five levels; new "i" suit)
Elastigirl spans three levels (she appears in two more as either a guest or a helper)
Elastigirl (one level; original suit)
Elastigirl (two levels; new "i" suit)
Dash (two levels, both of which have a time limit). Two suits: secret identity and supersuit.
Violet: Used once. She sneaks past guards invisibly; the supersuit is her only costume. Unlike the others she is defeated with one hit.
Incredi-Ball: Dash and Violet together in a force field.
On the GBA version, Incredi-Ball is absent. However, the character of Frozone is playable, and in addition, Elastigirl as the form of a boat is playable. Violet is also playable for two stages instead of one.
Source: Wikipedia, "The_Incredibles_(video_game)," available under the CC-BY-SA License.