I can't decide if this is a serious question or not. But no, it's not a Trojan.
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That's what a scammer would say.
This one does not even have mosaic censoring typical for dlsite... ;-)
But seriously, there are many games uploaded here with malware in it, often pulled from dlsite - or steam for that matter. Or any other site. Often with the criminals impersonating as the creator and even linking to the correct patreon or steam. Chances are, that one of your games also was used for this or will be used in the future.
Sadly, itch does not do it. Not properly. I have seen files that were detected by virustotal, yet were hosted on itch.
My whole point is, that questions like this are prudent. There is several malware games a day that slip through the net and appear alongside the legit games. At the time the question was asked there might have been a surge of dlsite games. It almost was a sure bet, any game remotely looking like one was malware. I am not joking. If you go to recent adult games on a weekend you will find a dozen or more of that crap.