Slot Sequels: Why Do Some Succeed and Others Fail?

by James Gibson 23.10.2026

Whenever an online slot is a success with players, there’s a chance there’ll be a sequel at some point. This makes sense, but sequels don’t always repeat the success of the original.

Slot machines in a casino © Amit Lahav Unsplash

Why Slot Sequels Are Created

Look through a typical online casino’s games library and you’ll find loads of online slots. There’s a good chance that you’ll come across some slot sequels in the collection too.

The companies that create online slots, commonly known as providers, want their slot games to perform well. In other words, they want lots of players to spend plenty of money placing bets on them.

When a slot does well, the provider might decide to create a sequel. The reason for this is straightforward: if the first one has been a success, the same should be the case for a follow-up (in theory at least!).

It’s similar to movies. If a movie is a commercial success, there’s probably going to be a sequel in the next few years. If that performs well, there might well be a third instalment, and so on.

When a slot goes down well with players, you can’t blame the provider for wanting to capitalise on its success. After all, it’s a company, and it needs to make money.

Creating sequels can be more profitable than focusing on standalone titles. Having said that, not every follow-up matches the success of the first instalment. Some slot sequels, for one reason or another, are flops.

What Are Slot Sequels All About?

When a provider creates a sequel to a slot, it usually has the same theming and design features as the original. It also has more or less the same gameplay mechanics, though there can be some changes.

For example, the second instalment might have more paylines or a higher RTP. It may also have a special feature that wasn’t in the original slot. The idea is to make it more appealing than the one before it.

If the second one has the exact same mechanics and features as the first, but only looks a bit different, it’s not going to attract attention. Part of its gameplay needs to be different so it appeals to players.

The theming and design are important as well. In a typical slot series, no two instalments are completely the same in terms of their appearance. Changing the look is as important as updating the gameplay.

This blog post covers a few slot series, including some that have been huge hits and others that have performed badly. We’ll try to determine why some have succeeded, and others have failed.

The Big Bass Series by Pragmatic Play

We’ll start with a series of slots that’s hugely popular right now: the fishing-themed Big Bass slots by Pragmatic Play. The first title, Big Bass Bonanza, came out in December 2020.

Thanks to its success, its provider soon released a sequel: Bigger Bass Bonanza, which had a release date of September 2021. The original Big Bass Bonanza online slot was a hit because of its theming and features.

Its highlight is the free spins round, which introduces the fisherman wild. Whenever this symbol lands, as well as acting as a wild, it collects and pays the cash prizes on all fish symbols.

This particular feature ties in with the fishing theme exceptionally well and adds to the slot’s immersion. What adds to its appeal is that it only happens during the free spins round.

Big Bass Bonanza wasn’t the first fishing-themed slot – Reel Time Gaming’s Fishin’ Frenzy series started in 2014 – but it was still a success for Pragmatic Play. As of October 2026, the series has around 40 instalments, including future releases.

The provider keeps expanding the series because individual titles continue to go down well with players, which can be said for the series as a whole. Slots keep introducing new features and new takes on the fishing theme.

For example, Big Bass Bonanza Megaways uses the popular Megaways mechanic. This gives players up to 44,656 ways to win on every spin. Big Bass Amazon Xtreme takes place in the Amazon river.

It builds on the free spins round seen in the original by adding enhancers such as symbol removal and guaranteed fish on every spin. Some other slots worth playing are Big Bass Halloween and Big Bass Trophy Catch.

The Immortal Romance Series by Games Global

Back in 2011, Games Global released the Immortal Romance online slot, which is themed to vampires and the romances they have with humans. The slot remains hugely popular to this day thanks to its theming, design and gameplay.

Played on a 5×3 grid, the slot has 243 ways to win and on any spin, up to five reels can become fully wild. There are four main characters, each of whom has their own soundtrack and free spins feature.

Amber’s free spins round is available when you start playing. The other three are unlocked one at a time after five, 10 and 15 free spin triggers. Each one gives you a different number of spins and different enhancers.

Immortal Romance 2 was developed by Games Global’s partner Stormcraft Studios and came out in 2024. Though it retained many of the same features and introduced some new ones, it didn’t have the same impact as the original.

One of the new features is the Bloodline Bar. This doesn’t affect the gameplay at all. Instead, it tracks your spins and unlocks music tracks, skins and backgrounds as you reach milestones.

The four free spins rounds are present in the sequel, but they’re all available from your first spin. The chances of triggering free spins, however, are lower than the original Immortal Romance slot.

Immortal Romance 2 sounds impressive and certainly has enough features to make its gameplay enjoyable. However, it’s safe to say the slot hasn’t completely lived up to the hype.

This could be because there was a gap of 13 years between the first and second instalments, and the first one was – and still is – loved so much. It can be argued that expectations were simply too high.

The Energoonz Series by Play’n GO

Play’n GO released the Energoonz slot back in 2013. This zany, sci-fi game introduced players to the Goonz, a species of colourful, squishy aliens that come in all shapes and sizes.

Part of what made the slot stand out and grab players’ attention was the design of its aliens. They appear as symbols on the 5×5 grid, and each one has individual traits and characteristics.

The slot’s gameplay was also well rated by players. Unlike most other slots, this one has paylines running both horizontally and vertically, plus there’s a cascade after each winning spin and a free spins round.

Energoonz was successful enough that Play’n GO decided to create a sequel: Reactoonz. This has become one of the provider’s biggest releases to date. It takes the core concept of Energoonz and builds on it.

Reactoonz is played on a 7×7 grid and uses cluster pays to determine wins. Cascades are still in place, and there are a host of new features to make its gameplay even more exciting.

For example, there are four Quantum Features that can be triggered, one at a time, after collecting enough winning symbols. The slot also has extra wilds and a 3×3 Gargantoon wild symbol.

The Reactoonz online slot went down very well and has spawned a sequel of its own: Reactoonz 2. Other instalments in the series include Gigantoonz, Gargantoonz and Reactoonz Blitzways, all of which feature cute aliens and similar gameplay features.

The Nitropolis Series by ELK Studios

Some series can spawn dozens of slots, whereas others last a few years before the momentum slows and player enthusiasm dies down. This seems to have been the case with the Nitropolis slots.

Developed by ELK Studios, the slots are about four clans of animals in a post-apocalyptic world who are fighting for Nitro, a substance that powers their cars. They’re gritty, action-packed games with a long list of special features.

The first one, Nitropolis, came out in 2020 and was well received. It has spawned no fewer than nine sequels and spin-offs to date. The fifth main instalment, Nitropolis 5, didn’t fare as well as the first to fourth ones.

It has a lot in common with the previous four slots and it introduces some new features. Even so, it didn’t have quite the same response as the titles that had come before it.

Perhaps the other four slots had covered so much ground that there was little for the fifth one to offer. Or maybe they were so full of features that fans wanted to play something with a bit less going on.

Even though Nitropolis 5 might not have had the same impact as others in the same series, it’s still worth playing. It’s a suitable slot for anyone who likes unpredictable gameplay with all sorts of features lined up.

The Risk of Creating Slot Sequels

Providers create sequels hoping they’ll be just as big as the slot(s) that came before them, if not bigger. Sometimes this pays off, and a series goes on to enjoy a lot of success.

Sometimes it doesn’t pay off and a sequel, whether it’s the first or tenth in the series, falls flat. The success of a slot sequel can’t be predicted with 100% accuracy. Still, providers are prepared to take the risk.

This is a good thing for players because even if a slot doesn’t perform as well as others in the same series, at least the provider has tried. Plus, it gives players another slot game to try their luck on.