The Mummy Slot: review of Collapsing Reels feature
There is a bonus feature in The Mummy Slot which triggers other bonus features, including Collapsing Reels.
During this game the symbols on the reels not spin, the symbols fall down. It's the cascading reels. But there is a bonus feature: all symbols in any winning combination explode to exempt a place for new falling symbols which can form a new winning combination. But Airship Free Games symbols and Mummy Hunt symbols do not explode.