I have an older 32-bit Windows XP system I use for retro gaming, in part because I can use it with a CRT monitor for pixel art style games like this.

While older builds of this game (v2.1) works on that system, the latest version does not. It simply gives me a "this is not a valid Win32 application" error.

I know that Windows XP is no longer officially supported, but it would be nice to still be able to download older versions of the game that still work on that system.

I am fortunate I have offline backups I downloaded years ago from GOG.com, but if I ever lose those copies, there isn't an option to download those older versions anymore.

Please make older Windows XP versions available through GOG. Thank you .

Unfortunately latest versions of Adventure Game Studio don't support Windows XP anymore.

Using the Galaxy client's rollback feature you can revert back to a previous version of the game, but the problem is that Galaxy doesn't run on Windows XP either.
Maybe you can use Galaxy on a different PC in order to download an earlier version of the game and then transfer it to the Windows XP PC.

I know it's a bit late but ...

You can always use the 64 Bit version of Windows XP (which I had back in the days)

Also it's supported by ScummVM.