thanks for the quick answer, that's a bummer. win7 is perfectly fine for what I'm using it for, which is pretty much everything. I see no point in constantly upgrading everything just because there's a newer version. if the current one works fine and the new doesn't do anything I care about, fuck it, especially with new versions always introducing more annoyances, bugs or fluff. I have a potato that still runs most of my unplayed games, though some clients unnecessarily blocking win7 make it harder.
a lot of games, old and new, run on older versions of unity and have no problems. pretty sure your game, which is just basic solitaire, would've been fine too, had you not opted for the latest version, then it would've reached a wider audience (puzzle/casual people not into the latest hardware/software). I also have a potato laptop with win10 but solitaire is not something I'd like to play there. or anything really, hate laptops, but it's a necessity sometimes. linux and virtualbox fuckery sounds like too much work only for this, I'll just wait until I get a new pc, plenty of other solitaires to play until then.