do you have to pay for it if you download it and what do you press to play it after downloading it
well it should be the extact same as long as you can access your downloaded files.
also heres a download link for "7-zip" like i mentioned earlier - https://www.7-zip.org/download.html
Once 7-zip is installed, right click on the downloaded file for THIS game, and click extract to [INSERT GAME NAME HERE] and then open the extracted file and you should find the game there, if you do see it, open it and you're good to go.