Some TRONish stuff. I guess you could say it's a bit of a Journey/TRON crossover, with a little bit of Flower and The Endless Forest thrown in somewhere.

Journey: http://thatgamecompany.com/games/journey/
Flower: http://thatgamecompany.com/games/flower/

Brushes used:
http://www.brusheezy.com/Brushes/2231-Infinity-Brush-Set
http://www.brusheezy.com/Brushes/13319-MB-ArtisticSet-II