This is a puzzle-like mini game. You will encounter some Elves each level. They are fighting for the only qualification to the next level. You should help them by sliding. When you slide an Elf, it will go straight the direction till it hit another one, and then stop. Keep doing the same thing until the last Elf survives.
Each Elf can be slid, so you will never known which is the winner. Come challenging and see how far you can go!