There are two versions of the game. The actual games are the exact same. One exe and one is blorb. Blorb files require the Inform interpreter to play them. You can get one here:
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The blorb version exists because some people get paranoid because their antivirus complains about the exe version because it has the interpreter built into it. So the author releases the blorb version for those people. If that all sounds confusing, just download and play the exe version, ignoring any false-positives your antivirus may complain about.