Yeah, sorry about that. The door pieces are not very visible behind the gems, was my next priority but didn't have time for it.
Thank you for playing and for your feedback :)
I must admit, I took most of the system from Code Monkey's match 3. It's simply a time-based linear movement between two positions, you can take a look at it here : https://github.com/ffortat/sacrimatch3/blob/73d8fb089e832723cf5a23e99c7defbbeee2...
Thank you, glad you enjoyed it :)