The setup of the board is very interesting. The first and the last reel have 3 symbols on them, while the middle four reels are one row taller to begin with, and then the symbols can split too, so you can have a total of 7. This means you can have a maximum of 34 symbols on your board, in which case you'll be playing a game with 21,609 ways to win. You pay 20 coins to spin the reels, and the bets can range from €0.20 to €100. Main game and paytable Not only that the board looks different on every spin, but this is a cascade game, too, so all the winning symbols will explode and will be replaced with new ones coming in from the right. Every time that happens, the win multiplier will increase, and you see the current value on the top left. There is no limit to the multiplier. The paytable has six card symbols, which is plenty, and the Purple Gem and Green Gem also belong in the same group, so we could say there are eight low-win symbols. Yellow Gem is a bit better but not by much, and the only powerful symbol is the Blue Gem. It even pays when you land two of them – you get 1x your total bet for that – and it pays better for four-of-a-kind than any other symbol in this game pays for six-of-a-kind. It's obvious that it's more difficult to land a full payline win if the game has six reels than if it has five, and if we're talking about five-of-a-kind wins, you can get 1.50x your bet at best, with the exception of the Blue Gem that pays 15x. This is a high variance game in which you'll rarely get the best wins allowed by the paytable, as the win frequency isn't that high to begin with. When you do win, it will likely be a small win that covers your losses, and the big ones will be coming only from the Blue Gem, the consecutive cascades that increase the win multipliers, and from the free spins game. Bonus features You trigger the free spins game in the usual way, by landing the Scatters, and the maximum number of Scatters you can land is six. You'll get 9, 15, 21 or 27 free spins for three, four, five or six Scatters respectively, and every time you land a Spin Scatter during the feature you'll get +2 extra free spins. There's no limit to the number of free spins you can get. Also, it's interesting to note that the win multiplier can carry over from the base game to the free spins game. Perfect Gems Slots RTP Perfect Gems has theoretical return to player (RTP) of 96.50%, which is excellent, especially since variance is high. You don't normally see that very often. Either the slots have high variance but then you pay the price of getting a lower RTP, or the slots have high RTP but then keep the variance medium, even low, to protect themselves from huge wins. This game has the best possible combination of high RTP and high variance. Conclusion It takes patience to play Perfect Gems because the game has high variance and you will probably need to wait for a while before you land that big win, but fortunately the RTP is very good so you can indeed play for a long time without losing money. It's an excellent slot that has an interesting base game and a very rewarding free spins feature. What more can you ask for? Visit a good Play'n GO casino and play Perfect Gems for real money.