@arek that's sad to hear, Arek. My PC tried to block the game too, have you tried to run the .exe as administrator? That may help.
Glad to hear you like the graphics of our game!
EDIT : Hey mate, I really want you to enjoy our game, so I looked up a fix from 'pmacdonald' :
> Open Avast
> Double-click the "Avast" icon on your desktop or locate and run the Avast executable file on your computer to start Avast.
> Navigate to Avast File System Shield
> Click "Real-Time Shields" in the column on the left of the Avast interface. From the drop-down menu that appears, select "File-System Shield."
> Open Up List of Exclusions
> Click "Expert Settings," and then click "Exclusions." This will take you to a list of programs that are exempt from Avast's File-System Shield blocking.
> Add Your Games to the List
> Click the "Add" button and navigate to the .exe file of the game that Avast is blocking from running. > Select the .exe and click "Open." It will now be added to the list of exempt programs and Avast will no longer prevent it from running.*
Hope this helps you!