Having watched this several times I noticed a riffing quality that reminds me more of good oldschool MST3K than a lot of the other offerings.
It's because the guys let themselves relax and get goofy in a sort of stoned way, or a way appreciated by the mind of someone in that condition, perhaps.
I loved the little songs, like "Car Ride" and - especially - the "Tubeworm" song. That was frickin' hilarious.