It's utterly insane that someone would release a 32-bit game in 2016, let alone leave it 32-bit in 2020. It's inexcusable, really.
Well, when they get around to recompiling and fixing this for 64-bit targets, I will likely buy it. I could play it now with a compatibility layer, but honestly, why bother? There's plenty of 64-bit games I could play instead.
As I wrote before, the problem is not the game itself (which is written in C#) but the underlying engine (Unity), that was 32bit only on macOS until early 2018 (which was very surprising to me, when I found that out). Additionally the main target platform for games is usually windows and maybe consoles, so unless the devs use their own engine or the macOS (and usually Linux) version is made by a company for which porting games to macOS is a main job (and by that is aware of those problems), the devs use windows for developing the game and probably only do some tests on macOS. And that is usually enough, since nobody would expect that a game engine, that offers a 64bit version on windows, is 32bit only an OS that supports 32bit software but that is mostly 64bit (and that quickly dropped support for PowerPc processors a few years back).
So yea, it would be cool if they release a 64bit version of the game, but the question is: would that pay off? Because they would either have to update the engine on their own to 64bit (which requires access to the source-code, which they don't necessarily have, the corresponding development tools and knowledge about these tools), or they would have to update the game to a newer version of the engine (which would require a lot of work since there have definitely been some changes in the meantime and most likely cause a lot of bugs). And besides that, they would have to do that for all plattforms, since they can't just update one platform to another version of engine, because that would make fixing bugs extremely difficult.