Yeah that annoyed me lol. I turned it on just to see what it looked like (blank digital face) and then couldn't get out of it lmao. Maybe charging it would fix it, but my charger was in the other room, and... you know.
I tried Power Reserve mode and found that Activate on Wrist Raise doesn't work, and clicking the button brings up the time but it takes about 2 seconds so feels like the watch isn't responding.
One thing John Gruber mentioned is in the 20+ days he's been using the watch he's never needed the power reserve mode. Used it once and that was just for his review. Also said most days end with 40-50% battery life left.
I tried Power Reserve mode and found that Activate on Wrist Raise doesn't work, and clicking the button brings up the time but it takes about 2 seconds so feels like the watch isn't responding.