There are some hard climbs. Any idea which you got? I haven't tried Ven Top (Mt Ventoux, in the France world, obviously) yet. In Watopia, the Alpe du Zwift took me 80 minutes. The radio tower climb, also in Watopia, is a bit less demanding, and the volcano climb is quite short and fun. I've just found
this review of the Alpe by someone who knows the real climb, on which it is closely modelled, well.
Coming down the hills again is different. You can't crash, and there are no brakes. Doing 60mph round the hairpins was pretty unnerving, even though I knew it wasn't real. I don't like heights at the best of times. But the miles going down count towards your experience points as well, and you have just pedalled up - whether or not the route finished at the top.
I'd suggest doing most of the rides by choice (collecting the badges) first. Then you can do something to your taste. I haven't bothered with Surprise Me! yet - I'm keeping that for when I run out of new routes.