There are 3 levels, each one gets harder. You control the dog. Use the left arrow to go left, right arrow to go right and space bar to jump. Collect all the bones (all 3) to open the portal. When you have collected all 3 bones, the portal will start flashing. When you go through it, you will be transported to the next level. If you touch any junk food, (the cheese puffs, cake or donut) GAME OVER! Good luck!
Tell me which level you found hardest in the comments section.