Hi, Valentin and Adrian, we are happy to see fellow developers searching for interesting games around. Thank you for your review and comment, it's really a pleasure to know we're not alone.
ThatRPG was our probe game to find if there are any audience for hardcore puzzle action/adventure games with a lot of struggling thru "tendency to look for easier solutions instead of right ones". We found its audience to be quite small, less than 300 people in total. Maybe next time we should try more colorful graphics and less steep difficulty curve, yes.
As for third riddle you can read sign near it again after meeting the Lady and the hero will tell you how to compute the right answer. Beware of negative numbes, though!
Eugenia & Vladimir