Book Of Demi Gods IV - Thunderstorm is a video slot game developed by Spinomenal. This slot game is inspired by Greek mythology and features thunder and lightning as its central theme. It has a standard 5x3 reel layout and offers players 10 paylines to win. The game includes various symbols from Greek mythology, such as Zeus, Poseidon, Hades, and Athena. One of the unique features of this slot is the expanding symbol mechanic, where a chosen symbol expands to cover the entire reel, potentially leading to bigger wins. The game also offers a free spins feature, where players can win additional spins and increase their chances of winning.