. Microgaming & Gong Gaming joined forces to release Royal League Neptune's Harem slot with its classic theme and RTP of % for every player to enjoy! Royal League Neptune's Harem has a jackpot prize of up to x your stake and a free spin feature. Royal League Neptune's Harem. The developer's gaming library consists of video slots crafted to run seamlessly on mobile and desktop devices. (5 votes) | Vote this page! Microgaming Casinos. Play For Free LeoVegas Casino Jackpot City Casino Nomini Casino Casino CASINO OF THE MONTH. Play at [HOST] for real money and get a Welcome. LeoVegas Casino The last feature is Neptune's Harem's Royal League jackpot, which is totally random. +. The 20 payline slot game is visually pleasing, with the reels sunk to the bottom of the ocean. There is a free spin feature that can award you up to 12 spins. Play For Free. Titles like Piggy Luck, Neptune's Harem and. Spin City Lux.