Final decision: Due to difficulties in compiling a Linux version that works of even just a small test app, I do not plan to proceed with cross-platform. Sorry.
So, in doing the V2.00n mostly-rewritten code, I'm wondering whether people feel it's worthwhile aiming for cross-platform? I will stress that this won't be a matter of "every system in existance" - I don't at all plan to target Android, or homebrew-capable consoles, for example. I have my doubts about even going for Mac, for the simple reason that I will most likely never own a Mac myself and thus will be unable to test. However, Linux is a realistic possibility; I now have a secondary PC, which runs Ubuntu, so I am able to test a Linux version. If I switch over to Lazarus - something I'd quite like to do regardless, if possible - then it shouldn't be too difficult to also create and support a Linux version.
On the other hand, the benefits of such aren't too huge, since WINE exists.
How many of you's use Linux, and if so, do you think that a native Linux version of NeoLemmix would be a good thing to aim for? I will stress that the Windows version will always remain the primary version.
(If there's much benefit to be had, a native 64-bit Windows version is also a possibility, though I don't see much need for this as the 32-bit version runs fine on 64-bit Windows.)