It's funny about Joust. I never tested it in MAME, apparently.
I've known about Serpentine for ages. I thought that I submitted the fix for it, but clearly not.
A couple of other games had the same requirement.
I think that Pooyan and Lady Tut also rely on uninitialised memory, but the effects aren't detrimental.

Yes, Hero is very sensitive to the joystick calibration.