Apparently, an official port exists, but Google refuses to sell it in America.
What really makes this eggregious is that Visual Arts do not appear to have a zero-tolerance xenophobic stance like Minori. I bought Kanon from U.S. iTunes, so there's no veto problem or rights problem. It's just purely Google being evil assholes. Now please excuse me while I clutch my $10 and shake in impotent rage.