Poochy IS Stupid. I don't care what the level title says. One thing you'll find about the Extra stages is that that odd numbered ones are all really hard (probably the 3 hardest levels in the game), and the even numbers ones are relatively easy.
Anyways, the most important things to remember are that Poochy always runs in the direction you are facing when you're riding him, and that Poochy always runs faster than the screen scrolls -- thus, if you face the same way too long, Poochy will run off the screen and kill you. (Thus, change direction every so often if you're about to run off the screen, or jump off Poochy for a short time and land back on him to stop him altogether. The trick is just memorizing where all the "level traps" are and preparing for them one at a time.
Even knowing this, I fail this level quite a bit myself. This level can be really hit or miss, especially with how erratically Poochy moves sometimes. Perhaps Fifth has advice that may help you more than mine?
