So, I'll go with a few positives.
First, the defense really did a great job. They kept the Vikes in the game a lot longer than they should have.
Second, nothing in the game makes me think McCarthy isn't the long term answer at QB. He had a rough game but he kept his head down field, even when running. I think a lot of the bad things that happened weren't his fault and, with more experience, he'll be just fine.
A few negatives -
The o-line was horrible. As Nick stated, O'Neil struggled. On the strip sack, the line blocked down and O'Neil didn't even put a hand on the edge rusher who had a straight line to the QB. That was clearly a pre-snap blocking call (Jurgens? McCarthy? O'Neil?) that was screwed up by somebody. And, kind of like the Rams playoff game, KOC didn't adjust much to fix it. Oliver wasn't often put in, for example, as a pass blocker to help Skule. I thought both Fries and Jackson mostly were pretty good up the middle but the edges and Jurgens were a bit iffy.
Second, we had some opportunities and didn't convert. Some stupid penalties hurt. McCarthy missed Nailor on a (likely) TD and Nailor made a few good catches for him on some other bad throws. Growing pains. But it hurt.