Is it common that Windows Defender program on our computer warns us with the message "unknown author" before installing a program from itch.io? And, if not, how do you prevent by our application from generating this event?
You'll need to sign your executable to avoid this issue:
https://msdn.microsoft.com/en-us/library/ms537361(v=vs.85).aspx
Thanks for the encouragement, dear Leafo, but could you download and run: Bacci & the Ducklings (DEMO), to see if it is really like you say? You only need a few minutes and I would be very grateful to you ...