Home » New Slots to Play in May 2021 | Week 1

New Slots to Play in May 2021 | Week 1

Rise and shine! The sunny month of May is upon and so are numerous new slots that are bound to lighten up our gaming week. Will you headbang to the tunes of Hammerfall or rather prefer total reel mayhem caused by Sergeant Nitro Wolf? Whichever it may be, there is one release that should have everyone’s attention as it comes with an exceptionally high RTP. Read on to find out.


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4th May 2021 | Relax Gaming – Book of 99

Been seething at the latest trend towards lower RTP settings or games being offered with RTP ranges? Well, Relax Gaming has the perfect answer with Book of 99. As the name suggests it is a “Book of…” style slot with a never-before-seen RTP of 99%, clearly showing that developers can create entertaining slots with virtually any RTP.

Book of 99 Screenshot

Played on the usual 5×3 grid with 10 fixed pay lines, you can bet from 0.10 to 100 credits per spins. New is the collection meter, accumulating scatters when no feature is triggered. Three or more scatters or collecting 99 will trigger the usual 10 Free Spins with one pay symbol being randomly selected as the special expanding symbol. Over 12,000 times bet have been achieved in a single feature in test simulations.

4th May 2021 | Elk Studios – Nitropolis 2

Had the feeling that the chaotic mayhem on the original could be outdone any time soon? Elk Studios’ Nitropolis has been such a success that they went back to the drawing board to create a sequel less than a year later. Nitropolis 2 is bringing back Sergeant Nitro Wolf for another action-packed reel chaos as he hunts own the Dirty Dawgs, Gritty Kitty and Pug Thugs gangs.

Nitropolis 2 Screenshot

While the betting range has remained unchanged, the number of ways to win has doubled to a staggering 191,102,976 thanks to a pay-both-ways modifier. New is a horizontal reel on top of the game window filled with Nitro Boosters that will further enhance the Nitro Reels if they appear on the same reel. Witness the ultimate mayhem in the free spins when Nitro Reels turn sticky and wins could reach 10,000 times your bet.

6th May 2021 | Play’n GO – Hammerfall

They sure do love their heavy metal at Play’n GO. Judging by the amount of Rock Slots they have released to date, I wonder sometimes whether they blast the music through the offices every day. This week, Swedish power metal band Hammerfall joins the likes of Sabaton, Black Mamba, Helloween to feature on a branded game, whereas on this occasion Play’n GO went again for their favoured grid format with the usual plethora of modifiers and features.

Hammerfall Screenshot

The 7×7 grid slot allows bets from 0.20 to 100 credits per spin, delivering a reel carnage with random Destruction features, Lightning Wild multipliers, Hector’s Hammer, three Song features and Hammerhigh Overcharge mayhem. Get headbanging and you might return from this reel performance with wins of up to 30,000 x your bet.


That about sums up the highlights of the the first May’21 week. Plenty to look forward to although rather low in numbers. The three mentioned however deliver suspenseful gameplay with ample twists and new features as well as top win potential. Check back next week when we will present more new slots to play at your favourite casinos. Or browse through our list of tested online casinos if you are looking for a new gaming hangout with a big welcome bonus.

Let’s Play!

Team GMBLRS

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