I will be working on my Gachapon system at long last. <3
The front-end animation will be done with jQuery and CSS. For a live example,
click here.
My plan is for it to cost 50 tokens to operate. You can earn 10 tokens every week if you're in the top ~20% of active, participating players. Otherwise, the tokens are planned to be a real money currency. On the other hand, you might win tokens via other means or right back from the gacha machine itself (not much more than it cost to play, though).
With this in mind, it's time start thinking about
chests, since the premise is very similar. (The difference is that gachapon is a page that will grant a random item, while a chest is an item that will grant a random item. The code is similar, the location is all that varies.) I hope I can get back to everyone about this sort of thing soon. :3