The mysterious object (the box with a question mark) is a new feature that we have developed recently in order to add more challenge to the game.

You can consider collecting the mysterious object first when you still have more space. Once you know clearly what object that collected box is, you can continue to match and resolve it.

Special objects are a real challenge, so don't rely too much on luck when dealing with them. You need to have the right strategy to overcome this challenge.

Be patient with new objects and try to push your own limits!