Also, that's why I didn't use irrKlang for TurboSphere. I'm quite done with 32-bits, I only compile TS for Win32 because I know I can count on most people who can't or won't compile it themselves being able to run win32 programs.
Actually, unless you need to full capability of 64-bit (i.e. access to more than 4 GB of RAM, unlikely a 2D engine like TS would ever need that much), the general recommendation has always been to build for 32-bit anyway. It won't be any slower (32-bit isn't emulated like 16-bit is, you're using real Win32 binaries), and compatibility is better.