Nitropolis 4
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Nitropolis 4 Slot Review

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How to play Nitropolis 4 mobile slot

The Nitropolis 4 slot gives you 4096 ways to win, where the avalanching wins and expanding wins give you progressively more value for money and a top win of 50,000x your bet.

Elk Studios has been creating Nitropolis slots for years and very successfully. The idea is simple: set in an apocalypse where dogs and cats rule the world. A literal dog eats dog, cat eats cat, world.

Th Nitropolis 4 slot game is all about expanding the reels. From increasing the game to 8 rows high to the nitro reels where symbols you can hide up to 6 symbols high, to all symbols possibly coming as mega symbols of 2×2 to 3×3.

Randomly, you can get bonus features to help you on your way to wins, from pay both ways to multipliers and free spins where the reels don’t reset between spins.

Nitropolis 4 slot is a mid to high-variance slot

Which follows the tradition of the Nitropolis 1 slot and the Nitropolis 2 game. The difference here is that you can win 50,000x your bet rather than 10,000x. That’s a big jump.

The problem is that you get hurt via the RTP – whereas the sequels all had 95% to 96%, the RTP for Nitropolis 4 is set at a low 94%.

You do have to be careful as you walk into this Old Rig of the future. The apocalypse is a harsh world, but if you dig for long enough, you might just strike gold.

Lots of features and action

The good news is that despite the RTP, there’s enough action and features that you rarely get bored. Having those reels expand on every pin, and never quite knowing what feature will get, is exciting for any player.

And whilst you can win big on any win, thanks to the Nitro multipliers that can multiply each other and appear at any point, free spins will give you huge wins.

Why? Because all the Nitro Reels stay sticky, and the expanding reels don’t reset between spins. You’ll love this slot game if you can get to the top quickly and get plenty of bonus features and multipliers.

A perfect companion piece for slot machines such as the Propaganda slot or Taco Brothers Derailed, but not one to play on its own for hours unless you are all about risk.

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Nitropolis 4 slot stats

Mobile Slot releasedFebruary 2023
Slot typeVideo Slot
Slot reels / paylines6 Reels / 4096 Ways to Win
House edge / RTP6% / 94%
Slot volatilityMedium/High
Min/Max bet0.20 / 50
Max win50,000x your bet
Free spins8 to 20 Free Spins / Sticky Expanding Reels and Sticky Nitro Reels
Bonus roundsAvalanching Win, Expanding Reels, Multipliers, Wild, Stacked Symbols, Scatter, Free Spins, Symbol Upgrades, Respins
Slot ThemesAnimals
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In-game bonus features

Nitro Reel: This always at least covers two symbol positions and contains 4, 6, 8, 10 or 12 identical 1x1 payout symbols. A big Nitro Reel always covers 6 symbol positions and contains 2, 3, 4, 5, or 6 identical 2x2 payout symbols.

Mega Symbols: All symbols, including the wild, can come as 1x1, 2x2 and 3x3 size symbols.

Wild: The wild symbol is not only the highest-paid symbol of the lot but can substitute for all other symbols except bonus and the super bonus scatter.

Nitro Multiplier: This blocker can appear in a Nitro Reel. It will hold a multiplier value of x4, x6, x8, x10 or x12. It multiplies all wins in view. The Multipliers will also multiply each other.

Avalanching Wins and Increasing Reels: Every symbol part of a winning way to win will explode, leaving empty spaces to be filled with more symbols. An additional row is then added to the top, up to a maximum of 8 symbols high.

Nitro Booster: These two screens at the top of the game may give you added boosters before the main reels stop spinning.

  • Both Ways: The game now pays left to right and right to left
  • Redrop: Keeps the bonus, wilds, multipliers and nitro reels and gives you a free drop of the reels for an extra chance to catch bigger wins.
  • Max Rows: Expands the game to 8 rows high automatically.
  • Garbage Collect: Selects one random symbol and removes all instances from view.
  • Nitro Appear: Randomly places a Nitro reel of any size in the ongoing spin.
  • Nitro Wild: Selects an existing Nitro Reel and fills it with wild symbols
  • Nitro Upgrade: Selects an existing Nitro Reel and upgrades the symbol within to a higher paid symbol or a bigger multiplier.
  • Nitro Match: It changes the nitro reel symbol to one on the reels to guarantee a win.

Scatters and Free Spins: 3 or more bonus symbols will trigger the free spins bonus. You win the super bonus if one of those is a super scatter symbol.

  • 3 bonus symbols: 8 free spins
  • 4 bonus symbols: 12 free spins
  • 5 bonus symbols: 16 free spins
  • 6 bonus symbols: 20 free spins

In a normal Nitropolis 4 slot Free Spin bonus, each time you add a row, the next spin starts at that row, up to a total of 8 rows. All Nitro Reels are kept and remain in play for the bonus duration.

The Super Bonus Game is played with Max Rows, and Both Ways is activated.


  • Huge 50,000x stake max win
  • Free spins with sticky expanding reels
  • Avalanching wins with expanding reels
  • Up to 12x multipliers


  • Low 94% RTP

Nitropolis 4 Review Conclusion

The Nitropolis 4 slot has the lowest RTP of all the series, set at just 94%. It makes it hard to give this game a 5 star review, even though it has the highest top win of all at 50,000x your bet.

Is Nitropolis 4 worth playing? Absolutely. It's fun, has plenty of great features, and has some of the biggest wins we've ever seen.

It's actually not as volatile as Nitropolis 3 slot game; however, giving this a heads up on its predecessor and we'd play on 4 over 3 any day.

But if you've never experienced this series, maybe start from the beginning and work your way up.

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Review by Lucky Mobile Slots, last updated: March 9, 2023 - Rating 4

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