Sometimes Victor Gijsbers gives you everything you need to understand one of his works within the context of the work itself (The Baron, Fate) and sometimes you can't get the full picture without external information (Vampires). So when Victor releases a game on September 11th called The Game Formerly Known as Hidden Nazi Mode, and it contains both source code and an accompanying essay explaining his original goals, I find it hard to believe that this is merely the well-packaged remnants of a failed experiment.
So once we get past the cute cover-art bunny that has a vague resemblance to a certain WW II leader, what do we have? Emily Short has already analyzed the apparent argument posed by the game as released: if TGFKAHNM has truly had its hidden Nazi mode stripped out, how would we really know? Sure, we can inspect the source he provided -- even build it ourselves -- but since a compiled version was included, how can we know that version was built from the source that's in front of us? Could I7 source be obfuscated sufficiently to hide this material in plain sight, even with access to the source? Probably. In fact, it would be theoretically possible for an IF compiler to include a "Hidden Nazi Mode" that injected objectionable material into otherwise unobjectionable source text.
This line of argument risks being taken to sophomoric extremes, however. Emily correctly boils this down to an issue of trust; at some point you have to trust your toolchain, or trust the author(s) of the games you choose to play. Or not. Either way, you make a decision to play or not, and that decision may or may not turn out to have been wise.
But let's go beyond the surface argument. Victor didn't have to release this game with the title he did, nor with the essay that spelled out what was originally in the game. He particularly didn't have to do so and also release a precompiled version of the game.
What if Victor had simply released the source code to a game called Fluffy Bunny Friends, saying only that it was, perhaps, a mildly interesting experiment with integrated personalization and tutorials? But for the highly suspicious circumstance that it would be Victor Gijsbers releasing a game called Fluffy Bunny Friends, would anyone have spent time scouring the game for hidden anti-Semitic content? Had he also provided a compiled version, would anyone have seriously entertained the notion that the compiled version of Fluffy Bunny Friends might not correlate precisely to the provided source? I don't think so. In my opinion, it's fair to say that his intentional choice of title, intentional inclusion of the backstory essay, intentional inclusion of a compiled version of the program, and the possibly intentional choice of September 11 as the publication date all add up to a package deliberately semiotically charged with threat.
And indeed, when you are thus sensitized, there are certainly plenty of unsettling things to find. The prominent challah bread and other traditional Jewish food that is described as "not being appealing to you". The bookcase, filled with books by Jewish authors. Ignoring all the external, non-game context, these are arguably neutral references; it's certainly not inherently wrong to set a rabbit hunt game in a Jewish neighborhood, and not everyone likes rice pudding. But you as a human player can't actually ignore everything outside of the game, and so instead these same details of setting and description take on a darker character in the light of what you bring into the game. Even the personal references by the narrator seem somehow oppressive, and the mere act of searching for and feeding cute little bunnies takes on sinister overtones.
TGFKAHNM is amusingly subtitled as a "game for unattended children". Let's assume that there is no actual programmed hidden Nazi mode -- that Victor played fair with us. You could put this game down in front of a child who didn't know what the word "Nazi" meant, and they would have an enjoyable few minutes searching for bunnies and feeding them carrots, and never connect that experience with anything beyond that. Those of us who do understand the references and symbology Victor uses, though, can't help but become sensitized, and subsequently perceive the exact same game in the light of that sensitization -- literally, we have pre-judged it, and that prejudice colors our perceptions. And in that respect, the hidden Nazi mode is real after all, but it's inside our own heads.