I was looking at the Demoscene announces, and just stepped into this Williams Pinball machine emulator, which is totally impressive.
https://playfield.dev
I really like the concept. It enables the full emulation/debugging of legacy pinballs by running the firmware code and emulating all i/o (display,m buttons, solenoids, lamps etc). The UI of the debugger is neat, too. And it's open source. https://github.com/neophob/wpc-emu
Posting this here because I believe some of you may like it.