Poto & Cabenga takes the one-button formula - ie. your character is running left to right and you tap a button to make them jump (see: Canabalt and Robot Unicorn Attack for the examplars of the genre) - and doubles it.
No, you don't have two buttons; instead, you control two characters with the one button. Hold space and Poto (or is it Cabenga?) will run faster. Release space and Poto (or is it Cabenga?) will jump. But when you press space Cabenga (or is it Poto?) will jump. And when you're not pressing or holding anything Cabenga (or is it Poto?) will run faster.
Both characters have their own obstacles to negotiate and their own collectibles to snatch. It's basically the gaming equivalent of patting your head while rubbing your belly.
What's your high score?
Poto & Cabenga [site]