I started with enthusiasm, but it soon cooled off when even finding the starting point was far from easy. For an hour I wandered near, only to discover that I had to go to the first stage! Then, it had a few inconsistent indications, as to look for a statue in a place where there wasn't any... Probably hidden for maintenance. The assistance was mainly by bot, that is, they can only give you standard answers to standard questions.
The idea was great, but the realization was poor. I did another Questo game in Rotterdam, and it went much better (I could complete it, while here I had to give up after many hours). So probably the problem wansn't me, or, not only me.