Kind of confused why people would try to run/compile/etc. Flash games on modern platforms.

If this game were a native app from that era, you'd think nothing of whipping out a Windows XP VM and installing an era-appropriate toolchain in it.

And really, the same applies not only for native executables, but to any proprietary / non-standards-based format from a previous era that's since been left to the wayside. Want to use a website that embeds a Java applet? You'd better (effectively) time-travel to 2005.

IMHO, at this point, a Flash game (for which the source code is not available) should really be "modernized" similarly to the way the Internet Archive makes old Windows and Mac software available — by wrapping them up into their own little standalone VM images. Like this: https://archive.org/details/chips_challenge_windows_3.x