Relax Gaming’s Book of 99 slot features a monstrous Cyclops and an old Greek tale. A bonus round in which growing symbols flood the reels as they land on them is included in this 5-reel, 10-payline game, making this Relax Gaming piece super attractive. Stakes range from 10p to £100 per spin, making the game accessible to players of all budgets and skill levels. An incredibly high RTP of 99 per cent is what sets Book of 99 apart from the rest.