Open the extracted amanita august 1.1 folder, then open the file that says application (it should have an anime girl or mushroom icon). You don't need a program to launch it!
i dont see application. i see game, lib and renpy folders, and then AmanitaAugust.exe, AmanitaAugust.py and AmanitaAugust.sh .py seems to open some python code, sh is a text file and .exe opens a folder somehow