This is a really slick jackpot machine, with nice reel animations, exploding coins and other players to bet against.
"This is a Free to Play Classic fruits slot machine game. Your objective is to spin the reel and hit any winning combinations. Jackpot pays up to 4000 credits. You can bet 1, 3, 5, 10 or 20 coins at a time, which gives different multiplications from 1 to 4. Free credits replenished up to 200 credits every 10 minutes if you have less than 200 credits."
There's also the source code available to an earlier slots experiment in this github repo.