Element DS is inspired by the Flash game called “COLLISO DS” created by kurohako. The DS version has been redesigned and made from scratch and features about 160 levels. The objective in game is to remove all the blocks by dragging them toward the blocks of the equal symbol/color. Two blocks of different color will reverse/swap their colors once they collide. The Blocks won’t stop until they either hit another block or the walls, meaning that they travel either horizontally or vertically unless they meet the obstacle in their path.

http://www.neoflash.com/forum/index.php/topic,5258.0.html