I have tried playing in both opera and brave. Both have the same problem.
i don´t know if you are facing a real bug, but here is some tutorial for you (I will add the tutorial in the game´s page)
1.at the start there are two pieces in screen (represented by the number 2) , so you need to select one. It will be added to your pieces
2. after this you press the buy button (represented by the number 1) , and two new pieces will apper in the screen.
3.when you get one of each type of piece you can create an human (represented by the number 3)
I hope the problem is not a real bug, i´m sorry for the misunderstanding.
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