Lot of good stuff there. Here's how I saw the Good, the Bad, and the Ugly.
Good
Rosen made a lot of good throws, regardless of whether they were caught or not.
Rosen didn't throw any INT's and with the exception of a few 50/50 balls, didn't really look like he was giving the ball away. Very solid outing. Good ball security.
Extended plays where he could and exhibited good pocket presence overall.
Took a sack when necessary and threw the ball away when needed.
Didn't fumble the ball nor really expose himself to INT's.
Saw the defense well and didn't get caught confused as most defenses try to do to young QB's.
Lots of good progression reads.
Quick analysis of coverages and separation.
Quick translation from what he saw to the ball out of his hand and to the receiver.
Generally put the ball where his guy could catch it, even when his ball placement was off (usually too high, which is a good sign because that's easily correctable and common for young over-excited QB's rushing things or not concentrating on their footwork).
Didn't hold onto the ball too long. Got the ball out quickly, even on deep throws.
Very good accuracy on deep throws.
Composure under pressure.
Never had a "deer in the headlights" moment.
Bad
He had a lot of bad throws, including ones that were completed which were made much harder than they needed to be or limited/prevented YAC chances.
Overall about half of his passes were poor (20 of 39 I'd call poor passes), but most were near misses rather than wild or dangerous throws.
He didn't orchestrate even one TD drive. Ultimately, those are what make QB's good, so he's gonna have to start converting drives eventually.
Ugly
That hospital ball to Hurns that caused him to have a concussion looked like a rookie mistake. To Rosen's credit, he referred to it as one of the lowest points of his career so far, so he realizes and regrets it.
Conclusion
All in all, it wasn't a productive offense, but I can definitely say that was the most encouraging game I've ever seen Josh Rosen play. This is the first time it seems like he might just be building towards eventually realizing his potential. Kudos to ya kid, this was a breakthrough game despite not generating even one TD for the offense. Now we know you have it in ya … it's just getting it out more consistently.