Also the game costs 20 bucks but it's offered as "Free" with "in app purchases". But you can only play one challenge until you need to buy the game. That's just false advertising. Just be upfront about it and sell the game for 20 bucks instead.
The link I used is the one from your site.
But you're right, the tutorial is playable too and it consists of the same kind of challenges, not just simple explanations how to play. So my initial statement was not correct.