Io Slot

Io is a sci-fi themed Io slot from ELK Studios online slots. Io features some unique gameplay elements. It plays out over 6 reels, with 4,096 ways to win. Tumbling symbols add ... Read Review

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Reviewed by Jim Tomlin

Slot Information

Slot Information

RTP: 96.00% Volatility: Medium Maximum win: $500,000.00 Progressive Jackpot: No Bonus Feature: Yes
Elk Studios

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Io Review

Io is a sci-fi themed Io slot from ELK Studios online slots. Io features some unique gameplay elements. It plays out over 6 reels, with 4,096 ways to win. Tumbling symbols add more real money winning ways and extra rows, so you can end up with a huge 262,144 different ways to line them up for a prize.

Other exciting features include Charged Wilds that stay active, multiplier wild symbols and lasers that create even more wild symbols. During a free spins round, these wilds collect at the bottom of the game for even bigger wins. You can grab a prize equal to 5,000x the stake, or 500,000 credits at the maximum bet.

Take a virtual trip to one of Jupiter’s moons when you play the Io online slot on a PC or mobile device at our top-rated casinos. Learn about other online slots at and check out some no deposit bonuses as well.

Meet Our Slot Tester

Jim Tomlin

Jim Tomlin

With more than 20 years of experience in online gaming and Sports journalism, Jim has keenly tested, played and reviewed a multitude of slot games, looking for characteristics that differentiate them in terms of themes, features and jackpots before they reach the market. When Jim finds a slot game he likes, he just keeps on spinning, going for the win. Not much we can do about that!

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Io Online Slot Setup, Controls, & Paytable

The Io online slot plays out on a portrait-oriented screen, with the controls either to the sides or below, depending on whether you play on a PC or mobile. Those controls work in just the same way and give you a wide real money bet range running all the way from just 0.20 to 100 credits per spin. You play with 20 coins, and just click on your chosen bet level to get started.

Other control buttons activate autoplay and fast spin modes, and the little “i” tab opens up the paytable. Here, you can see how much you win from each symbol when it crosses at least 3 of the 6 reels. Each symbol is in a circle, and they fit together in a zig-zag pattern, making the Io online slot from ELK Studios look unique.

Inexperienced players might be put off by this unusual layout, but it’s pretty easy to grasp. has best slots bonuses but you can also see our freeplay version of the Io online slot if you’re unsure about its gameplay.

Play Io Slot on Mobiles

The portrait style fits naturally on the screen of a smartphone, and the Io slot machine is a great game to play from your iOS, Android, or Windows device. You won’t miss out on any features, options or rewards when you play on a mobile.

Slot Features

  • Multipliers

  • Scatters

  • Wild symbol

  • Free Spins

  • Expanding reels

  • Sticky wilds

  • Random wilds

  • Multiplier wilds

  • Cascading Reels

  • Retriggering

Io Online Slot Gameplay Features

The sci-fi theme runs through the Io slots game. The reels sit in the window of a spacecraft, against a backdrop of deep space, with a purple planet looming behind. Bright playing card symbols, stars, lucky clover, diamonds and red 7s fill the reels.

The red 7 that pays the most, returning 500x your coin value, so expect to see it across the reels less often than the lower value card symbols. Those are worth between 20 and 35 coins.

Charged Wilds, Free Drops & Other Io Bonus Features

Players arriving at this ELK Studios game from our online slots game providers will find that the Io online slot is packed with out-of-this-world features. All symbols in a win vanish from the game and others roll in from the adjacent reels as new symbols drop from above to fill the gaps. An extra row appears on top, boosting the number of ways to win from 4,096 to 15,625.

If that creates a new combination, the process repeats, with a further row added. This can go on until you have 8 rows of symbols, and 262,144 winning ways in this real money slot.

You also benefit from Charged Wild symbols that act as others to complete combinations; they stick around until they have helped to complete 4 combinations. Single lasers shoot across the reels, removing symbols and double lasers do the same, but leave wilds behind.

Three bonus symbols launch 7 free drops, which play out on the full 8 rows of symbols at no cost. During this feature, wilds collect at the bottom of the round, helping to complete lots of combinations.

Io Online Slot Max Payouts, RTP & Volatility

You can win 5,000x your real money total bet during the free games round, which equals prizes up to 500,000 credits if you have the maximum stake of 100.00 on the triggering spin. This is a medium to high variance game, where payouts come in at an average of 96% -- players who enjoy the top New Jersey online slot sites or Pennsylvania’s best online slot sites will know that this is right about average for RTP.

Our Io Rating & a Similar Online Slot

We loved playing this game. It’s very different from others, with symbols rolling onto adjacent reels and extra rows added on any win. The medium to high variance means you won’t get a win on every spin, but prizes can be quite high in value to compensate.

If the Io online slot is a little too “alien” for you, try the more conventional 5-reel, 25-line Star Scape online slot from Microgaming. Check out our range of top-quality online and mobile casinos here on to see where you can play these space-themed games.

Check out all the popular free slots games.

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