Mysterious is a video slot in a 4×4 format with 256 ways to win in the base game. The grid will increase to a 6×4 size with 4,096 ways during the two free spin features. Wins are awarded for three to four and three two six matching symbols respectively on adjacent reels from left to right only. You can enter the haunted mansion on desktop or mobile from 0.10 to 100 credits per spin. The game has maximum volatility (5/5) with a default RTP of 96.50%. Some operators might opt for a lower RTP setting, always read the help file to find out which version you will be playing.