Players report that Book of Poseidon by Booming Games offers an engaging underwater adventure filled with ancient Greek mythology. The slot features a classic 5-reel setup with a unique twist, as the 'Book of' mechanic introduces expansive wilds and free spins, allowing for exciting gameplay. The community finds that while the graphics are visually appealing and the soundtrack complements the theme, the game's volatility can lead to extended dry spells. Many players appreciate the potential for big wins during the free spins feature, which can be triggered by landing the special books. However, some users have noted that the base game can feel a bit repetitive, with fewer winning combinations than expected. Overall, Book of Poseidon is seen as a solid offering from Booming Games, particularly for fans of mythology-themed slots who enjoy a balance of risk and reward.