Use A and D or the arrow keys to move Doge left and right. Get to the green without touching a Doge-Head (OW!) to level up. Each level allows one more Doge on-screen. Try to get as far as you can and maybe even beat the High-Level!
OW! It's just some silly thing I made up... Might or might not update it in future. Credit to @TheDiamondDoggy for loving Doge and to all the sound-effect creators (some were made by @TheDiamondDoggy)