[Laforet]

I am not too worried about anything pre-2000 as emulation has got really good over the last few years, just in time as the surviving legacy hardware became prohibitively expensive to acquire. The internet archive has also made it easier than ever to access old software.

What concerns me are early 2000s stuff with DRM and server-side content to make preservation difficult if not impossible.

[throwaway48476]

Cloud anything is also a huge red flag for preservation.

On the other hand there is a game I played on PowerPC macs but the developer released it on github and now it's been updated and compiled for ARM and x86. As long as source is available it's usually not very hard to port to a different architecture.