Some friends of mine recommended that I play this game, which looks like a delightful riff on Xevious (one of my all-time favorite shoot-em-ups). So I headed over to the OpenTyrian page.
However, the current OpenTyrian downloads on Google Code are infected with a fairly common Trojan virus, according to Avast, which won't let the download continue.
I've tested the few other downloads available on the 'net other than the one through Desura and they're also coming up with the infection notice. So it's specific to the file, not necessarily a successful attack on the Google Code page (although they probably also got their binaries through there...).
I'm not qualified to judge whether it's a false positive, but Avast's record on this stuff is pretty good.
I strongly recommend that the current builds be tested very thoroughly to make sure they're clean and until then, redistribution of the current binaries isn't recommended; it may have already infected hundreds of machines.
I built them myself (they're cross-compiled using mingw32-gcc on Arch Linux), and the builds are hosted on my server because Google Code doesn't host downloads. I suppose it wouldn't hurt to include an md5sums file somewhere on the downloads page. Of course, if you don't trust my builds, the source is there for inspection and compilation by anyone else.
Most likely it's a false positive. Out of curiosity, what exactly does it claim it's infected with?