So, I did once own a disc copy of Expendable and it came with some hardware around Christmas 1999. That disc is long gone now. I've seen the game pop up on PhilsComputerLab a lot in testing and he repeatedly said that the game crashes when the CPU is faster than 1ghz or so and he showed that on multiple systems. However there is a release of the game on Steam which obviously runs on faster CPUs somehow. On a whim I decided to just copy the Steam version folder into my WinME machine which runs a Celeron 450 2.2ghz CPU. It works in Win10 with multi core, multi ghz CPUs, so why not, right?

That just works. I ran it at 1600x1200 and beat the entire first level without any issues at all. Though stencil shadows didn't seem to be rendering at all.

So, I thought I'd just report that. Sadly I lack an ISO of the original release and I've so far been unable to come up with one, only PS1 and Dreamcast version ISOs. Though I've ordered a loose disc on eBay today. (Maybe I can show up Teenage me and beat the game now? :V) I can compare results when it happens. I imagine that the Steam version has changed something and that change is backwards compatibility through to Win9X.