IO Slot Review, Demo Play, Payout, Free Spins & Bonuses

IO Review

The gravity mechanic that ELK Studios introduced with Cygnus (late 2019) is certainly a strong enough feature to carry plenty of games, something they seem eager to capitalize on. IO is Jupiter’s fourth largest moon, and the humorous backstory here is that a “casino space station” is waiting to access the earth orbit, and decided to mine some valuable minerals in the meantime. The game has plenty to offer in terms of features, but is it distinct enough from the predecessor slot to stand on its own two feet?

We’ll get to that in the conclusion of this IO slot review, but let’s cover some basics first. The gravity tumble feature is on full display at all times here, and it’s still fascinating to watch and highly entertaining. The volatility is still in the higher end of medium, and you can win up to 5,000 times your stake here too. So far, not much is different except the theme, but the bonus features are tweaked around enough to make this a pretty unique experience.

The most important base game feature is the Wild Forge, which creates a progressive win multiplier that has no upper limit. This can be really helpful when it comes to landing bigger wins, and you’ll also get help from a laser symbol that can create wilds and remove symbols. The base game in general has got plenty going for itself here, and we experienced very few dead spins in our 200 spins test session. The main attraction is the bonus round, however, as this is where things can really take off and go astronomical.

IO Slot Reel Screen

What symbols are there?

All the symbols in this game have a circular shape, and the 4 higher value symbols are golden discs with classic fruit machine lucky icons like 7s, diamonds and clovers. The lucky number 7 sticks out as the highest value symbol by far here, and all the royal symbols pay the same. You need between 3 and 6 matching symbols on a payline to win, and here is the paytable for IO slot:

• Lucky 7 - Pays 10x for 6 on a payline
• Pink diamond - Pays 2.4x for 6 on a payline
• 4-leaf clover - Pays 1.2x for 6 on a payline
• Blue star - Pays 0.9x for 6 on a payline
• Royal symbols - All pay 0.3x for 6 on a payline

What are the bonus features?

The gravity engine is working overtime on almost every spin here, as you’ll see winning symbols explode and make room for the remaining symbols to tumble wherever gravity takes them. A new bunch of symbols will also drop down from above, which effectively adds a new row to the setup and increases the winning ways accordingly.

Just like with a regular Avalanche feature, this process will not stop as long as you keep winning.

This can lead to significant winning streaks, where the game opens up more and more as extra rows and paylines are piled on top of each other. You can get up to 4 extra rows here, which means 8 rows in total, and this amounts to a staggering 262,144 ways to win. Here’s how it all works if you break it down:

• 4 rows = 4,096 paylines
• 5 rows = 15,625 paylines
• 6 rows = 46,656 paylines
• 7 rows = 117,649 paylines
• 8 rows = 262,144 paylines

The game comes with 3 wild symbols, 2 special wilds and 1 regular “w” wild. The regular wild will simply step in for all regular symbols to help you form winning combos, while the 2 special wilds are a bit more interesting.

The Charged Wild symbol has 4 lives (so to speak), which means that it can be part of 4 winning combos (including the full round of gravity/cascading wins) before the symbol disappears. It essentially loses 1 life per winning cycle it’s part of.

The Wild Forge feature will fill up an empty space below with a multiplier wild. Whenever the Wild Forge is activated (by cascading wins or dropping down), the progressive multiplier value will increase with no limit as to how high it can go. When the Wild Forge hits the bottom of the reels, the multiplier value will freeze and it becomes a regular multiplier wild.

You can also land Laser symbols here, and 2 intersecting laser beams will transform symbols into wilds. A single laser beam will simply remove all symbols in its way, and give you a new cascade and winning chance.

Free spins in IO slot

Despite all the base game action, it’s the free spins bonus round you’re really looking forward to, as usual.

You need to land 3 bonus scatter symbols anywhere on the same spin to trigger the free spins round, and the 7 free spins you get are played out on the maximum reel setup. This means you’ll benefit from 8 rows and 262,144 ways to win, and you can also retrigger the feature by landing 3 new scatters.

This gives you 7 new spins, which amounts to a maximum of 14 free spins in total. Both Charged Wilds and Wild Forge symbols are sticky and will thus pile up at the bottom of the reels. This naturally gives you a lot more action per spin. The Forge feature will create multiplier wilds that will be active on each spin, which makes the whole bonus round quite interesting and unpredictable.

How to play

ELK Studios games come with a very clean and modern interface, and it does not take all that long to get into this game. Still, we will take a closer look at everything you should know before you get started with the spinning here, and prepare you as best we can.

Experienced players might wanna skim through this part, or skip it completely, but beginners and newbies should read on.

You can start by clicking the hamburger menu in the top right-hand side corner, as this takes you into the IO slot paytable. Here all the different symbols and bonus features are explained for you in some detail, and you can also check out how much each winning combo is worth. The paytable is dynamic, which means it will change according to your chosen bet level.

You will also find 3 new icons you can click down below, and the gear icon takes you into the game settings menu. Here you can choose to turn on/off the music and/or the FX game sounds, or you can turn off/on all sounds as such. You can also turn on/off the Quick play feature, which is a very good idea in this game. The pace is simply too slow without it, not least because of all the cascading wins.

IO Slot Bonus Symbols

The “i” icon takes you into the game rules, where you can learn all the details about IO slot. Some game stats are revealed here too, and everything of importance is summed up with bullet points.

Finally, the time has come to choose your bet level between 20p to £100 per spin, and here you can also choose between 4 different betting strategies. The autoplay feature is simple enough, as you choose between 10 and 100 auto spins. That’s it, you are now ready to go on an epic treasure hunt in deep space.

Where to play IO slot?

There is no shortage of casinos that carry this game, as ELK is a popular developer. You already know all about how to play IO if you read through the segment above, and here we’ll present you with your best options when it comes to where you can play IO slot. The first thing you’ll need to do is decide whether or not you want to play for real money right away, or check out the free demo version of the game first. We are here to help you no matter what you choose.

Play for real money

If you have some casino experience, and have played online slots before, you might be ready to go for the real money action immediately. The good news is that we scan the whole casino market on a daily basis. This gives you the best overview possible of casinos that carry this game, and their respective welcome offers. Simply follow the link to the top of the review page, and you’ll be able to pick and choose where to play IO slot with a nice bonus offer to boot.

Play free demo version

We get that this game is somewhat unusual, not least because of the innovative gravity mechanic. For this reason alone, it can be a good idea to play the game for free first, before you risk anything from your own pocket. We have the free demo version installed right here on this page. All you need to do is follow the link to the top of the page, and you can check out IO slot for free via the demo game right away.

The 200 Spins IO slot Experience

Being fans of the previous and first gravity mechanics release from ELK, Cygnus, we were extremely eager to take this sequel for a spin. The mysterious title, IO, was intriguing enough, and the deep space theme looked really cool. Per usual, we went with a total stake of £1 per spin, and with eager anticipation we loaded up the autoplay feature with our first 100 spins.

We know this is supposed to be a medium to high volatile slot, but it did not feel that way to us, at least not at first. We kept getting plenty of action on more or less every spin, not that it amounted to all that much, but there were very few dead spins in our first 100 spin session.

We soon learned how important the Wild Forge feature is in this game, as we landed a 58.5x win thanks to plenty of cascades and a multiplier wild that went up to 7x in the end. This is how you’ll land bigger wins in the base game usually, and it gave us some really helpful wins to keep us going towards the free spins bonus round.

When we finally triggered the bonus round, we were deep into our final 100 spins, and we got 7 free spins for our 3 scatters. We had more luck in the base game really, not least after the bonus round “fiasko”, but we’ll get to that. We just saw too many dead spins in the bonus round to get any action, and in the end we won only 28x our stake, which was disappointing to say the least.

However, right after the free spins round was over, as if the game wanted to apologize, we landed a massive cascading action win of 84.95x our stake. This time the wild multiplier only went up to 4x, but more valuable symbols were involved. After 200 spins we more or less broke even, but we’ll be back for more gravity action for sure. We wish you the best of luck with your first spins on IO slot also.

Review Summary

If you enjoyed Cygnus, which is the first game in ELK’s gravity engine series, then you’ll probably like IO slot also. The difference is not all that massive, although it would be wrong to call it a clone. Of course, the theme is brand new, and so is the light-hearted backstory, but the game features and math model is somewhat similar. However, there are just enough tweaks and twists to make IO slot a unique experience, while still satisfying fans of the predecessor game. A cleverly done balancing act indeed, and we expect this is far from the last we’ll see from ELK’s gravity engine series.

Pros

• Gravity mechanics is still fun
• Wild Forge multiplier action
• Laser symbol transformation
• Free spins with sticky wild forge and charged wilds
• Medium to high volatility and 5,000x max win potential

Cons

• RTP is 0.1 % lower than the first game in the series

If you love IO slot you should also try:

Space travel and space mining is not the most common theme for slot machines, but there are still plenty of games out there for people who enjoy a bit of sci-fi. Here we shall recommend a few games we’ve handpicked particularly with IO slot in mind. You can read more about them via the link, and check out the free demo game if it’s available.

Cygnus - It’s only natural that we start by talking a little bit about the game that started this gravity mechanics series from ELK. Celestial bodies are involved here too, but the theme is also inspired by ancient Egypt and the pyramids. What sticks out in terms of features is the Multiplier X symbol, which can help boost your winnings up to 64x. This symbol is sticky in the bonus round, and you can win up to 5,000x your stake here also.

Neon Staxx - is somewhat in the same alley is IO slot, but only theme wise. NetEnt’s game has more of an arcade feeling than the deep space vibe, and it’s a lot simpler than IO for sure. Still, it’s worth checking out if you’re into futuristic games. The main attraction here is the Super Staxx, which gives you plenty of identical stacks of symbols. In the free spins feature, these stacks are only of higher value and wins up to 400x your stake is possible in this low to medium variance game.

Rocket Stars - might not take place in deep space at the beginning, but you’re getting there. It’s all about helping some cute “starmallows” build their rocket ship, and you’ll trigger the bonus round by finishing the project. This is when the game literally “takes off”, and you’ll benefit from a progressive multiplier with no upper limit. You can win up to 2,174x your stake in this game, and it’s of medium to high volatility.

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