I finally watched Rixty Minutes on the CC website. It was half funny, half self indulgent improv that didn't really work for me (with a few glaring exceptions...the Garfield one being the biggest). To be fair, I find almost all improv to be painfully unfunny as it tends to rely on the awkwardness of the situation instead of anything actually clever.
Maybe I'm wrong, but I think they drew the animated sequences and then had the voice over talent improvise based on what they saw. I got this impression at the end the of the Two Brothers trailer where the voice actor obviously couldn't keep a straight face anymore and started laughing.
But the story arc behind the tv episodes was outstanding.