The Trials open once you finish the last dungeon. :) the skilltree will be open after you enter your first portal :)Glad you enjoy it sofar. :)
I see, maybe add that somewhere :) I just unlocked the last dungeon, so let's goo
PS: Maybe add a button to early exit a Dungeon, with or without penalty, either would be fine imo. It's just unconvinient that you click on a dungeon by accident and have to do the whole thing. :(