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Io slot review

Added by Elk. Information last updated: 13/05/2021

User rating:

- (0)

Expert rating:

3.2 (1)

Game information

Game supplier: Elk

Release date:06/2020



Max. win:bet x 5000

Mobile version:Support all devices


Max. lines

Cascading reels

Expanding reels

Multiplier wilds

Sticky wilds



Riches & luxury


User ratings (0)

Game design:



Game sounds:

Mobile gaming:



Screenshot Screenshot Screenshot
RTP (Return to player):
Max. win:
bet x 5000

Bojoko score (compared to other slots on Bojoko)
Elk score (compared to other slots of supplier)

Expert's review Trystan Michielsen

Slot tested

Io is the very short name for the space-based slot by Elk Studios which brings the player into deep space where they are set to play with a series of cascading reels. The game further features expanding reels, multiplier wilds and sticky wilds.

Released in 2020, Io is a rather simple looking slot when it comes to the graphics with small balls that represent the different tiles. In the tiles are small, generic-looking symbols of things like stars and diamonds as well as the usual card letters. If this all sounds pretty basic, it does serve a purpose. With a 6-reel, 4-row playing field that can grow to hold a maximum of 8 rows the slot needs a lot of room for these extra tiles.

The background shows that we’re in deep space with a starry sky and an alien planet in the distance. It’s not terribly original and very simple, but I appreciate it isn’t just a generic colour. The play area is also not very creative but this leaves more attention to the gameplay. There are several animations that trigger when certain features are activated but most of the game is static.


The symbols used for Io are not very creative, with most if not all of them based on generic symbols that everyone will be familiar with. Through the use of colour, they do stay distinct which is the more important aspect, especially as the playing field grows after consecutive wins. The game can have between 4,096 and 262,144 paylines on the screen at any given time so clarity seems like the bigger priority.

The symbols you’ll find in this slot include:

  • Bonus: Get 3 bonus symbols on the screen to activate the Free Spins mode.
  • Wild: Wilds substitute all regular symbols in the game.
  • 7: Max. 10x your bet with six-of-a-kind on a win line.
  • Diamond: Max. 2.4x your bet with six-of-a-kind on a win line.
  • Clover: Max. 1.2x your bet with six-of-a-kind on a win line.
  • Star: Max. 0.9x your bet with six-of-a-kind on a win line.
  • Ace: Max. 0.3x your bet with six-of-a-kind on a win line.
  • King: Max. 0.3x your bet with six-of-a-kind on a win line.
  • Queen: Max. 0.3x your bet with six-of-a-kind on a win line.
  • Jack: Max. 0.3x your bet with six-of-a-kind on a win line.

The game uses a number of different features to help create multiple wins at once which is why the payouts for a single win are so low. Nonetheless, getting a big enough win requires several things to go right which puts it at High Volatility. Players can augment their experience somewhat by picking a bet between £0.20 and £100 per spin.


Io has a number of features that augment the gameplay in subtle and less subtle ways, but in general the game functions as a normal slot, it just looks different. The game uses round tiles which I thought meant it would use a cluster pays mechanic, but it doesn’t. Io still uses regular paylines to calculate wins.

You’ll encounter the following features here:

  • 262,144 Ways To Win: The game grants a win for any symbol that appears on consecutive reels from left to right.
  • Cascading Reels: After a win is triggered, the winning tiles disappear and are replaced by new ones.
  • Expanding Reels: Whenever there’s a win, the game adds another row to the playing field, up to a maximum of 8 rows.
  • Wilds: Wilds substitute all regular symbols in the game.
  • Charged Wilds: These act as regular wilds but will remain in place for up to 4 wins on a single spin.
  • Multiplier: Anytime there is a gap below a Multiplier Wild, the game will fill that gap with a multiplier. This can go up to 20x your bet.
  • Laser: When two laser symbols on the screen shoot an intersecting beam, all tiles it touches turn into a Wild. A single beam will remove itself and all tiles it touches.
  • Free Spins: Get 3 Bonus symbols on the screen to activate the Free Spins mode. It’s possible to retrigger additional spins.

Most of the game takes place on the main screen. The features that are active during the base game are also present during the free spins mode. Activating the free spins mode was rather difficult for me, and I reckon that it will require multiple extra rows on the screen to have 3 Bonus symbols appear.

If you do manage to activate the Free Spins mode, the game will have all 8 rows activated the entire time. Charged Wilds and Wild Forge symbols are collected at the bottom of the screen between every spin.

Although there are a lot of features, I did not find the game difficult to understand. Most of the features are either active every spin or they do something that most people will know from other slots. There are different types of Wilds but essentially they all work to substitute other symbols, for example.

In Conclusion

Io is a very simple name for a rather simple-looking slot with a lot more depth in the features. The game isn’t for those that are looking for a rudimentary fruit machine, and it’s not quite inventive enough to satisfy experimental players.

However, for people who are looking for a slight departure from the standard 5-reel, 3-row slot with 20 paylines, Io might be exactly what they are looking for. The features are easy enough to understand while being influential enough to change up the gameplay.

The potential jackpot of max. 5,000x your bet is a sizeable incentive to try it out, but it will require you to hit the free spins mode and several more steps to reach the maximum payout. Instead, I’d recommend you just give the game a try for its original approach and see if that is enticing enough.

Overall rating:


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  • Features

    Wins and bets

    RTP (Return to Player):96%


    Max. win:bet x 5000

    Min. bet:£0.2

    Max. bet:£100

    Progressive jackpot:

    Reels & playlines



    Non-standard layout:

    Max. lines:262144

    Min. lines:4096

    Win both ways:

    Other features


    Expanding reels:

    Stacked symbols:

    Colossal symbols

    Auto play:

    Turbo play:

    Quick play:

    Virtual reality:

    Bonus features

    Bonus game:

    Random bonus:

    Progressive bonus:

    Buy bonus:

    Free spins:

    Scatter symbols:

    Bonus game symbols:


    Standard wilds:

    Sticky wilds:

    Walking wilds:

    Stacked wilds:

    Random wilds:

    Multiplier wilds:



    Walking re-spins:

    Sticky re-spins:

    Cascading reels:

    Sticky wins:


    You can play Io in English, Finnish, Swedish, German and 18 other languages.

    All supported languages:
    English, Finnish, Swedish, German, French, Spanish, Italian, Russian, Czech, Danish, Greek, Hungarian, Polish, Norwegian, Portuguese, Romanian, Slovak, Turkish, Thai, Vietnamese, Chinese


    Io supports GBP, EUR, USD, CAD


    Release date 06/2020
    20th newest on Elk 290th newest on Bojoko
    RTP 96% 0.04% < average
    37th highest on Elk 847th highest on Bojoko
    Win up to 5000 x your bet
    17th highest on Elk 452nd highest on Bojoko
    Paylines 262144 1310620% > average
    4th highest on Elk 13th highest on Bojoko
    Min bet £0.2 per spin
    7th lowest on Elk 625th lowest on Bojoko
    Max bet £100 per spin
    The highest on Elk 287th highest on Bojoko
    Rated 0 by 0 members
    The most rated on Elk 37th most rated on Bojoko
    57 more slots listed by Elk

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    Expert's profile


    Trystan Michielsen

    Trystan Michielsen

    Trystan Michielsen is a Dutch native who started his career as a content writer for various small businesses who were interested in creating an online presence.

    When the opportunity arose to move to Malta and work in the iGaming sector, Trystan didn't hesitate to make the plunge. Here he worked as a Content and SEO specialist for different companies before moving back home.

    Now acting as a freelancer he maintains his connection with the online slot community by playing and reviewing the wide variety of videoslots that are released.

    Trystan enjoys playing the slots that offer a full experience, focusing on more than just the technical details but keeping an eye on its presentation. Graphics, music and style can create a game that's more than the sum of its parts.

    A writer at heart, putting thoughts to paper is something he's done for as long as he remembers. In his free time, he enjoys writing fiction as well as watching and reviewing movies.

    Latest reviews:
    Io cover

    Game supplier:Elk

    Release date:06/2020

    RTP (Return to player):96%

    Max. win:bet x 5000

    Mobile version:Yes

    User rating: 0
    Expert rating: 3.2

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