I've only found one pre OS X game that actually worked properly in Classic and that's Dark Forces. Everything else has been unplayable or unusable.
I mean, it's great if you want to play Civilization 1, SimCity, or anything else that uses the OS 9's windowing system, there's actually a ton of games from that era that didn't go full screen and just used whatever the operating system offered. Windows didn't do nearly as well before 95 came out and DOS offered nothing. Of course if I'm actually going to play Civ1 again, it'll be the SNES version, but SimAnt or SimLife? Sure, SimCity 2000 has a 32-bit Window port everyone seems to have forgotten about which needs some hacking to work properly on Windows 10, but good luck playing 16-bit SimAnt or SimLife properly on modern Windows. Yes, Winevdm is a thing that runs 16-bit apps in 64-bit Windows, but it struggles with games every bit as much as Classic struggles with more demanding OS 9 and older Mac games.
And at that point, you're better off either running XP or OS 9, depending on the game.
I probably spend way too much time thinking about the easiest ways to play old games, even if I only really play maybe the same 10 old games when I get around to doing that.
Civilization 2 is my white whale. No, there is no good solution in getting it to work its best. The last 16-bit expansion, Fantastic Worlds is missing features compared to the only proper 32-bit release, Civilization 2: Multiplayer Gold Edition. That release needs patching to work in modern Windows, and has broken AI, the patching makes it unstable. And then there's Tests of Time, a whole separate thing. Why didn't I talk about the Mac versions? Because Mac only got Civ 2 and Civ 2 Gold. Did I mention these games use Redbook audio? And that Fantastic Worlds has more tracks than any other release, expansion or otherwise? And that none of the patching that Civilization 2: Multiplayer Gold Edition for Windows got has gone into the Mac version? About the only upside to the Mac version is that it works on 68k Macs, and that Basilisk II recently got support for mounting disks with audio. Shame it's not the Gold version, that needs PPC, and those emulators are terribly unstable, demanding mess.
Don't become me.