Bison are one of the most iconic animals in North America. Just like the bald eagle, they are American icons, and as such, they enjoy massive popularity in American pop culture. The bison is also a popular theme choice for slot developers, with dozens of bison-themed slots released. Northern Lights Gaming and Games Global's Bison Boom aims to become a standout in this market.

While most of these slots stick to the basics, this one does things differently. It has features like the Bison wild boom, moon symbols, and feature upgrades that can take your wins to the next level. The Upsizer feature makes an appearance, too, although it’s not common to see it in Games Global slots.

Animal totem collectors can bring the moon wins in, while adders add multiplier values to all the special moons. On top of that, splitters and other special features can make your wins even more exciting. Read my Bison Boom slot review below to learn what makes it unique.

Bison Boom is a 5x3 slot set somewhere in the American wilderness. You’ll see golden plains and rocky mountains in the background – a perfect setting for the Americana theme. As expected, the bison is one of the key symbols in the game. Other animals, including raccoons, eagles, and wolves, roam these reels as well.

The soothing soundtrack and high-quality sound effects create a very cool ambiance for the slot. In terms of layout, all the controls are conveniently positioned on the right side. From there, you can effortlessly select your bet, begin playing, or consult the game's paytable and guide.

Before you fire up the reels, you’ll need to set your betting parameters. Choose a bet between 20c and $20 per spin and hit the spin button to start. If you want to, you can set up to 100 automatic spins.

The action begins in the usual way: you need three or more matching symbols on one of the 20 active lines. A brown bear is the highest-paying symbol, paying 16x for five on a line. There are four premium animals and four card royals, in addition to other special symbols that come into play later.

During the base game, mini dynamite tokens can land on each spin. They are collected into the wild crate on the right side. As it fills up, it can explode and award the Bison Wild Boom feature. Up to 15 wild symbols can replace the regular symbols on the grid.

That’s the only feature available in the base game. Luckily, the slot makes up for the lack of other specials in the bonus round.

Bison Boom’s bonus round is activated by bonus scatters. You need three scatters to trigger Bison Spins, which is a twist on the popular Link & Win feature. Before starting, you can choose one of the guaranteed modifiers using the Upsizer feature for a fee.

It’s important to mention that the bonus round can also start with some pre-determined features active. The red and blue moons can land with multiplier values of up to x7. When two of them land, they add a token to the upgrade meter. Fill up all four slots to unlock rows in Bison Spins for an improved winning potential.

The bonus round will start with any unlocked rows and Upsizer features. It starts with three respins. Only moons, blanks, and feature modifiers can land on each respin. When a new moon or modifier lands on the reels, they reset the respin tally to three. The feature modifiers include:

• Collector: collects and combines all moons into one moon.
• Adder: adds multipliers of up to x20 to all the moons and lasts for a single respin.
• Persistent adder: persistently adds multipliers up to x20 to moons on each respin.
• Splitter: splits random moons into doubles or quads.
• Key: removes a lock from the reels.
• Bomb: blows up remaining locks to unlock all rows and adds a random number of moons to the reels.
• Doubler: doubles the value of random moons.

You can buy your way into the bonus round for 71.80x the bet. Some features, such as Upsizer and feature upgrades, are unavailable via the bonus buy feature.

Bison Boom took me by surprise. I must say I expected just another run-of-the-mill bison game you could find on any casino site, but got a great slot machine with plenty of features and unlockable winning potential.

The base game paid decent wins thanks to the TNTs and the Bison Boom.

I didn’t manage to land the bonus round, so I bought my way in. I was lucky to unlock one row and get a few splitters and doublers, eventually earning more than I paid for the bonus feature.

The Bison Boom slot RTP is set to 96.15%. The RTP can shoot to 96.57% with the Upsizer feature. The maximum win you can hit is 11,000x the bet.

Bison and animal-themed slots are not usually this impressive. Bison Boom may not have many features in the base game, but the bonus round with modifiers more than makes up for it. It’s got a charming character and offers plenty of excitement in the bonus round, so I can fully recommend it.

If you’re looking for an alternative, consider Bison Moon Ultra Link & Win with a similar bonus round. Or, if you’re looking for a progressive jackpot, you can check out Bison Fury by GVC.