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Unholy Mystery

7.9/10

Game provider:

Just Slots

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Unholy Mystery
7.9/10

Unholy Mystery Demo

Unholy Mystery Slot Review

Game Provider Just Slots
Minimum Bet 0.10
Maximum Bet 1,000
Maximum Win 10,000x
Paylines 20
Release Date 07/08/2025
RTP 96.36%
Mechanics Video Slot
Volatility Mid – High
Reels 5

Just Slots invites you to the wildest monster party in town, where fun, fangs, and freaky big wins are lurking beneath the shadows. Unlock the mayhem of Unholy Mystery and tuck into a variety of rewarding in-game features and a lucrative Free Spins mode.

Take your seat at the most terrifying dinner table, where a variety of questionable cakes and treats are on the menu. While the party is in full swing, there’s still a chance of you becoming part of the main course – at the very least, you’re walking out of there minus an eyeball.

During gameplay, players can feast upon wilds, mystery symbols, and an epic Free Spins mode with sticky mystery symbols. With a fixed RTP of 96.36% and a mid-high volatility score, we’re hopeful to get a taste of the 10,000x max win potential.

Just Slots is a smaller software developer with a big understanding of what makes an outstanding and innovative slot. In their fast-growing catalogue, you’ll find Cyber Egypt and Shogun Skylord, among others.

Being the ‘new kid on the block’ comes with its own challenges; however, Just Slots has made a positive impact on the iGaming industry by utilising innovative features and themes. On our agenda today is Unholy Mystery, but will it be all bark and no bite? Let’s find out.

Unholy Mystery Base Game
Unholy Mystery Base Game

Base Game & Features

Unholy Mystery is the latest mid-high volatility release from Just Slots, consisting of 5 reels, 3 rows, and 20 fixed pay lines. Winning combinations of 3, 4, or 5 matching symbols occur on adjacent reels, starting from reel 1.

The highest-paying symbol falls to the Wolf, followed by the priest, revolver, party hat, garlic, and 4 coloured religious crosses. Each paytable symbol awards a fixed payout between 0.1x and 30x your bet, where applicable.

Furthermore, Wild symbols appear on all reels and substitute for all symbols as part of a winning combination, except Scatters. Wild symbols pay 1x, 3x, 10x, and 50x your bet for 2, 3, 4, or 5-of-a-kind.

Wins are Awarded When 3 or More Matching Symbols Appear on Reels 1-5
Wins are Awarded When 3 or More Matching Symbols Appear on Reels 1-5

Mystery Feature

In the base game and Free Spins mode, Mystery Symbols can appear anywhere on the reels, revealing a random Multiplier between x2 and x100. Mystery symbols will reveal the same paytable symbol, excluding Scatters.

During gameplay, the Mystery Feature can be triggered at random. Once active, 3-9 Mystery symbols are positioned randomly on the reels, revealing the same high- or low-paying symbol.

Please note that additional Mystery symbols can land as part of the reels. All mystery payouts are combined before any win is awarded.

Between 3 and 9 Mystery Symbols are Positioned on the Reels During the Mystery Feature
Between 3 & 9 Mystery Symbols are Positioned on the Reels During the Mystery Feature

Hot Spin & Bonus Buy

Players outside the UK jurisdiction can purchase 2 Bonus Buy variations, in addition to a Hot Spin Feature:

  • Bonus Buy 1: Guarantees to trigger the Free Spins mode with 3, 4, or 5 Scatters for 117x your bet (RTP 96.76%)
  • Bonus Buy 2: Instantly triggers the Free Spins mode with 5 Scatters for 402x your bet (RTP 96.75%)
  • Hot Spin: Increase your chance of triggering the Free Spins Feature. Costs 200% of Base Bet. (RTP 96.33%)
Unholy Mystery Bonus Buy Options
Unholy Mystery Bonus Buy Options

Unholy Mystery Free Spins

Triggering the Free Spins mode requires 3, 4, or 5 Scatters to land in the base game, awarding 10, 12, and 15 Free Spins, respectively. During this round, Mystery symbols persist throughout spins, adding their values together for a combined total payout.

Unholy Mystery Free Spins
Unholy Mystery Free Spins

Our Honest Verdict

Unholy Mystery is a ‘spooktacular’ addition to Just Slots’ growing portfolio, and one we never knew we needed. The graphics are some of the best we’ve seen, while the theme is more of a rarity; however, both work very well together.

Just Slots may still be in their infancy, but they no longer need stabilisers when peddling out new releases, and they’ve certainly found their footing within the iGaming industry.

Unholy Mystery has all the right ingredients to be successful. It has an interesting Mystery Feature, sizable symbol payouts, and a rewarding Free Spins mode with sticky Mystery symbols – what’s there not to like?

During gameplay, Mystery symbols are the game’s main focus point, in both the base game and Free Spins mode. Furthermore, it’s a rather important piece when it comes to its persistent state within the Free Spins mode. Having additional Scatters and those few extra spins makes a whole world of difference to the outcome.

Our own testing of the game’s features led to some pretty impressive results, and that’s just through the standard Free Spins mode. There are definitely areas of gameplay that are far more compelling than others, leading to many exciting moments and high payout potential.

The potential we’re referring to is the 10,000x max win cap. This figure is what we consider an industry standard, but thanks to the available features, it does feel very achievable – and the RTP of 96.36% looks pretty solid, too.

All in all, a big thumbs-up to Just Slots once again. Granted, Unholy Mystery is not as enticing as Shogun Skylord or Cyber Egypt, but it’s a solid offering with engaging features, quality optics, and a promising max win potential.

*The images in this slot review are currently from Demo Play. On average, our reviews are written prior to the initial release date and before real play is available.