With that knowledge I gave it another try. It makes more sense now. I guess I some how missed part in tutorial where it spoke about 25 minutes. It's nice to have little mage in corner as reminder of your tasks, but I would recommend to add some audio feedback to make it more fun, and work as a reminder.
I guess I just had no mana, the blocks seems to work fine.
some blocks like scroll are blue but they quickly gain their colour is that a bug?
knowledge is not spent? I placed watch and scroll and lost no knowledge, only mana.
I had a problem with cauldron, I managed place it but after some time game crashed, and when I played again I couldn't place it, it was just appearing inside the mage. Any way I deleted save and tried again, it was working fine. I even restarted game to see if it works, and did. But after I tried to check one more time progress was lost and cauldron was again appearing inside the mage.