Looking over all the stuff going on with the arcade, I’m now realizing there are a lot of jackpots to be won. Having each of them pop up in chat would be too much clutter imo but having no spot for them would be disappointing, so I suggest something similar to the top score signs in bowling - but a jackpot ticker. It will show the most recently won jackpots by players globally across all arcades, from the top being most recent, and would play a sound when a player wins a jackpot. I imagine it to be on a pretty large screen readable from at least a distance of half the arcade room away to have a feeling of importance to winning a jackpot (as silly as that sounds, it might actually encourage more people than just a chat message or whatnot). Maybe a custom UI style too to be unique to the arcade?
tl;dr a big dynamic screen that shows the most recently won jackpots (globally) in the arcade