That led me to do a little searching, and I discovered that originally the game didn't work in Ruffle, as I apparently did something with the play game button that wasn't normal. But someone put a fix in it back in 2020[1] in order to get my game working again. That was pretty neat. Felt kind of nice that people still cared enough about my old game to make sure it still works in an emulator.
I'm glad these people are out there, getting these things working again. There's so many great animations and games that didn't deserve to disappear because Adobe decided it was a prudent business move to just drop all Flash support.
Still working on a more in-depth sequel (using Monogame), and I'm way overdue to make a new web version of the original. Might knock that out once I get closer to getting the sequel out there.
EDIT: Just realized Proximity is 20 years old this year. Huh. Probably needs a 20 year anniversary edition.