There's no such thing as a guarantee that something is virus free. However, the relevant point to notice is that the thing that gets "detected" (by 2 out of 70+ AVs, as had been noted) is the 32-bit .exe, a file which Virustotal also knows under other names - basically the name of every single porn game made with Ren'Py. This is because that executable is just the standard runtime that runs every Ren'Py game, the same file simply renamed for each game using it. And noting that this game uses
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, it can be easily verified that a) Ren'Py downloaded from the official website contains the bit-exact copy of our "suspicious" .exe (there generically called renpy-32.exe) which b) also gets flagged by the same 2 AVs as "infected" and c) has
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in Ren'Py circles as being occasionally detected as a false positive. So the TL: DR; version is that there are exactly two possibilities: either a large number of Ren'Py releases have been sitting on the official website* for ages actively being talked about yet somehow remaining infected all this time, or some AVs are just dumb and/or over-zealous and this is a false positive that affects ALL games made with Ren'Py..
* note that we're talking about a website that publishes pgp-signed checksum lists for all of its downloads, just so you can verify securely that you downloaded a pristine, unaltered file from them...
