Contrast, a platform/puzzle game developed by Compulsion Games for the PC, PlayStation Store, and Xbox LIVE Arcade, has a character that they would like you to meet: Didi.
Didi is a little girl who wants her parents to reunite, and is doing so with the help of her imaginary friend Dawn. Poor Didi, an adventurous and spirited little sprite lives with her mother; her father having left some time ago. Dawn makes up for his absense and keeps Didi company.
Dawn, like any other imaginary friend, has powers that allow her to manipulate light sources to distort, enlarge, or stretch the 2D shadowscape and then jump into that world to solve puzzles and navigate the world. As players play through the game, they'll unravel a story and solve the puzzles surrounding Didi's family.
Check out Didi's trailer: