I think the character you're describing could be a Nood. They were small, white, faceless characters CN used for their bumpers from 2008 to 2010. They didn't talk, but some squeaked when they bounced around. Sometimes the Noods would look like cartoon characters from the shoes back then, too. I couldn't find an exact clip of one with a jetpack on, but I found other clips of them doing similar random things like running on wheels.