Botmaster Steve Worswick, a.k.a Square Bear, creator of the popular
Mitsuku bot, has released a couple of cool free games in AIML, an
Anagram Game and a Slot Machine Game.

Slot machine style game Steve has also written a slot machine style
game in AIML with a "hold" feature. Make sure your bot doesn't comment
on repetition though, as it will probably complain after a few
spins. Type "luckyslots" to begin the game when you have loaded and
re-published your bot.

http://www.square-bear.co.uk/temp/luckyslots.aiml 

Again, Square Bear says, "Feel free to use it in your bots if you like it." 

His web site is http://www.bearbot.co.uk