Another thing you could try is submitting a false positive report to Sophos. Apparently this can actually work.
Ah, good find! I'll try that.
On a side note - the town and caves aren't supposed to look like that. I'm using the Windows terminal font that came with the system - apparently I was wrong in assuming it was available on all systems. I will investigate and see if I can figure out whats going on. What version of Windows are you on, by the way?
Really? They look like that for me, too. Windows 7, 64-bit.
Incidentally, since apparently no one but me is having this problem with the game being labelled malware, I'm just getting rid of Sophos. I did some digging and found that Sophos has been know to cause problems with various innocuous pieces of software. Moral of the story: don't use an antivirus programme just because your company gives you the paid version for free.
I'm genuinely sorry for any distress my difficulties with this have caused you. The last thing I want is to discourage someone from making their game. If I'd had any inkling that the problem was confined to just me and this ludicrous antivirus, I wouldn't have said anything.