Nitropolis 4 Slot Review
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Nitropolis 4 Demo
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3,000+
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Nitropolis 4 Slot RTP, Details & Wager Limits
The Nitropolis 4 slot is played on 6 reels and 4 rows and has 4,096 paylines. Winning combinations are formed by matching 3 or more symbols in any position on adjacent reels, starting from reel 1.
Stakes range from just 20p up to £100 per spin, which is typical of a lot of ELK Studios slots. Below the reels, you will see a coins icon. Hit this to choose from 1 of 12 predefined bet values. Autoplay and quick spins are also options in most territories outside the UK.
The Nitropolis 4 RTP is 94%, which is on the low side. When you compare it to the previous Nitropolis 3 slot, it’s a whole 1% lower. Volatility is high too, so don’t expect big wins too often. Again, this is higher than the previous release, which is in the medium to high range.
The maximum win is 50,000 x your total bet per spin or free spin. This is a very healthy figure and is up there with some of the best UK slots in the industry. Your best chance of landing the top prize will arguably come in the Free Spins feature as there are unlimited free spins up for grabs.
Theme – Nitro gangs are back!
The dystopian theme here follows on from the last 3 in the series. If you’ve played those then you’ll know that it’s a story about the Nitro gangs moving on to continue their dog-eat-dog lifestyle. In the previous release, they moved on to a tropical beach. Here, it looks like they’ve moved onto an oil rig. The clue is in the mug to the left of the reels – Eat, Sleep, Drill, Repeat.
The visuals are bold and colourful, with the audio sounding very industrial and futuristic. The symbol effects when things start to happen on the reels are great. It’s one of the things that really make this a great slot to play.
On the reels, the usual A-J Royals make up the lower-paying symbols. These are joined by higher-paying emblems and numerous bosses – rat, pug, kitty and dawg. The Dawg Boss symbol is the most rewarding, paying 1.5, 2, 2.5 or 3 x your stake for 3, 4, 5 or 6 in combination.
The game’s Wild looks like a spike mine, and it substitutes for all symbols except the Bonus and the Super Bonus symbols. Here’s a list of the symbols you will see on the reels in the game:
| Symbol | Payouts/Info |
|---|---|
 J | 3, 4, 5 or 6 = 0.1, 0.15, 0.2 or 0.3 x stake |
 Q | 3, 4, 5 or 6 = 0.1, 0.15, 0.2 or 0.3 x stake |
 K | 3, 4, 5 or 6 = 0.1, 0.15, 0.2 or 0.3 x stake |
 A | 3, 4, 5 or 6 = 0.1, 0.15, 0.2 or 0.3 x stake |
 Rogue Rats Emblem | 3, 4, 5 or 6 = 0.15, 0.25, 0.4 or 0.8 x stake |
 Pug Thugs Emblem | 3, 4, 5 or 6 = 0.15, 0.25, 0.4 or 0.8 x stake |
 Gritty Kitty Emblem | 3, 4, 5 or 6 = 0.2, 0.3, 0.5 or 1 x stake |
 Dirty Dawgs Emblem | 3, 4, 5 or 6 = 0.2, 0.3, 0.5 or 1 x stake |
 Rat Boss | 3, 4, 5 or 6 = 0.5, 0.75, 1 or 1.25 x stake |
 Pug Boss | 3, 4, 5 or 6 = 0.75, 1, 1.25 or 1.5 x stake |
 Kitty Boss | 3, 4, 5 or 6 = 1, 1.25, 1.5 or 2 x stake |
 Dawg Boss | 3, 4, 5 or 6 = 1.5, 2, 2.5 or 3 x stake |
 Wild | Substitutes for all symbols above |
 Scatter | 3+ triggers Bonus Game feature |
Nitropolis 4 Mobile
With ELK Studios being a mobile-first provider, all of its games are produced with the latest HTML5 technology. This means Nitropolis 4 can be enjoyed on iOS and Android mobile devices. It’s also available on tablets, laptops, and PCs. I do prefer playing games like this on a larger screen, though.
Nitropolis 4 Bonus Features
There are 13 bonus features to enjoy in the Nitropolis 4 slot game, and each one brings its own little bit of uniqueness to the reels to enhance the overall gameplay. Firstly, you’ve got the Avalanche mechanic, which can increase the reels up to 8 rows in height. You’ve also got numerous Nitro Boosters and free spins. Let’s run you through how everything works.
Avalanche feature
All symbols that form part of a winning combination will explode and leave the reels. This will make way for new symbols that will drop in, with an additional row of symbols being added at the top up to a maximum of 8 rows. The Avalanches continue until no new winners are formed.
Although there are 4,096 paylines, that can increase to 262,144 if you get the maximum of 8 rows, as per the following table:
| Rows | Ways to Win | Calculation |
| 4 | 4,096 | 4x4x4x4x4x4 |
| 5 | 15,625 | 5x5x5x5x5x5 |
| 6 | 46,656 | 6x6x6x6x6x6 |
| 7 | 117,659 | 7x7x7x7x7x7 |
| 8 | 262,144 | 8x8x8x8x8x8 |
Big Symbols feature
Super symbols 2×2 in size and Mega symbols 3×3 in size may appear randomly on any spin or symbol drop. it shares similarities with the Gold series of games with titles such as Tahiti Gold and Voodoo Gold. However, those go up to 4×4, whereas it’s just up to 3×3 here.
Nitro Reels feature
Nitro Reels cover 2 symbol positions in the Nitropolis 4 slot and contain 4, 6, 8, 10 or 12 1×1 payout symbols. Large Nitro Reels cover 6 symbol positions and contain 2, 3, 4, 5 or 6 2×2 payout symbols.
Nitro Multiplier feature
These will also cover 2 positions and will multiply all wins in view. You will notice a 10x multiplier in the base game screenshot above. If that was part of a winning combination, the win would have been multiplied by 10. Here are the multipliers on offer: 4x, 6x, 8x, 10x or 12x.
Nitro Booster
You’ll notice above the reels that there are a couple of displays. These can award Nitro Boosters on the main reels, which are exciting modifiers with 8 possibilities. These include:
| Redrop | All Bonus symbols and Nitro Reels are kept. Symbols are removed with new ones dropping in. The reels will then respin. |
| Both Ways | All ways pay left to right and right to left, which effectively means double payouts. |
| Nitro Match | An existing Nitro Reel on the reels is matched with a symbol in view and the Nitro Reel is filled with that symbol. |
| Nitro Upgrade | All instances of one symbol in view are randomly removed from the reels. |
| Nitro Wild | An existing Nitro Reel in view is filled with Wild symbols. |
| Max Rows | This will expand the game up to a maximum of 8 rows. |
| Garbage Collect | All instances of one symbol are randomly removed from the reels, triggering an Avalanche. |
| Nitro Appear | A Nitro Reel of any size is placed on the reels to replace existing symbols in view during the ongoing spin. |
Bonus Game feature
Land 3 or more Bonus symbols in the base game of the Nitropolis 4 slot to trigger this feature. Here’s how many free spins you can get depending on how many Bonus symbols land:
| Bonus Symbols | Free Spins Awarded |
| 3 | 8 |
| 4 | 12 |
| 5 | 16 |
| 6 | 20 |
The bonus round will always start with 4 rows. Each winning free spin advances the safety level 1 row up to a maximum of 8 rows. Nitro Reels and Big Nitro Reels may also advance the safety level several rows at once if they are stacked above the level that a regular win provides.
It’s important to note that during this bonus round, all of the Nitro Reels are sticky and will remain in place for the duration of the feature.
If you manage to land 3 or more Bonus symbols during the free spins, you will win additional free spins matching the number you needed to trigger the feature.
X-iter feature
Finally, you may have an X-iter feature which allows you to buy your way into 5 game modes. Unavailable to UK players, they will cost between 2 x and 500 x your total stake. Here are the options:
| Mode | Cost | Description |
| Bonus Hunt | 2 x stake | 1 spin with more than double the chance of triggering the free spins. |
| Nitro Booster | 10 x stake | 1 spin with 2 features from the Nitro Booster. |
| Super Spin | 25 x stake | 1 spin with Max Rows and Both Aways active. |
| Bonus Game feature | 100 x stake | Entry to free spins |
| Super Bonus Game feature | 500 x stake | Entry to the Super Bonus game |
Nitropolis 4 Review Summary – the RTP rate spoils its return
The improvements in Nitropolis 2 versus the original Nitropolis slot were OK. Then came number 3 with much-improved max win potential, so wasn’t it obvious that the Nitropolis 4 slot was going to be similar to its predecessor? I may have been expecting too much. I was excited to play this game and test it thoroughly, but although it is a fantastic slot, a couple of things disappointed me.
I was really hopeful that the RTP rate may improve. In fact, it’s gotten worse! With a low 94% RTP rate, I’m not sure it’s going to consistently attract players when there’s the option of Nitropolis 3 which is less volatile with a better RTP rate. But negatives aside, it still is a brilliant game to play. The visuals are great and the audio is as good as ever.
Overall, ELK Studios has pulled it out of the bag once again and produced a clever game with tons of bonus features. But how long before a much-improved Nitropolis 5 comes onto the market? Watch this space as it could well be sooner than you think.
Before we end the Nitropolis 4 review, here’s a breakdown of all of the important information on the 3 slots before this one.
| Slot | RTP | Max Ways to Win | Max Win | Bonus Features | Hit Frequency |
| Nitropolis | 95% | 85,155,840 | 10,000 x stake | 4 | 19.8% |
| Nitropolis 2 | 95% | 191,102,976 | 10,000 x stake | 12 | 20% |
| Nitropolis 3 | 95% | 1 Million | 50,000 x stake | 11 | 19.2% |
Nitropolis 4 FAQs
The Nitropolis 4 RTP is 94%, which is on the low side compared to a lot of other slots on the market. It’s also worth noting that volatility levels are in the high range.
The maximum win is 50,000 x your total stake, which is extremely healthy and up there with some of the best slots around. Your best chance of landing the top prize will come during one of the bonus features rather than the base game.
Yes, land 3 or more Bonus symbols to trigger the $1. You will start with at least 8 free spins and a combination of Bonus and Super Bonus symbols can trigger the Super Bonus Game which is played with Max Rows and Both Ways activated.
Yes, the $1 can be played here at Online-Slot.co.uk. Enjoy Nitro Boosters and unlimited free spins on mobile, tablet and/or desktop devices.
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Martin has worked for leading companies in the gaming industry and has a strong online casino background. He possesses extensive knowledge of casino operations, including bonuses, payment methods, and cashout times. His expertise extends to playing and reviewing slot games, making him a valuable resource.
