Modern online slot games offer stunning visuals, catchy sounds, excellent gameplay, and thrilling chances to win. And with thousands of unique games available, the opportunity for endless entertainment has never been more accessible. 

Many of these slots employ phenomenal bonus rounds that make them stand out from the masses. These not only make the game more fun to play but, depending on the game, can also reward the player with free spins. If used effectively, players can keep playing without digging into their available credit and (hopefully) win much more money. 

Although free spin bonuses are common in many slots, these bonus rounds are not all created equally. Some, like those listed below, offer more thrills and rewards and should be played by any gambler looking to maximise their time spinning online.

Cat Wilde and the Doom of Dead (Play n’ Go)

The daughter of a legendary slot game character is the perfect companion as you wander into ancient Egypt to discover the doom of the dead. The game is reminiscent of the iconic Book of Dead and will be familiar to anyone who has previously played the latter. 

Alongside the creepy mummies, which occur as stacked symbols, the game also has a variety of artefact symbols. There are also the common high-suit card letters that most slots feature. All these icons are spectacularly detailed and show how much attention was put into the game’s development.

The game’s features include expanding wilds, meaning exciting wins are possible if you’re lucky enough to land wilds on each reel. These will then fill the entire screen. Even this, however, pales compared to landing three compass symbols, which trigger the free spins bonus round.

Offering ten free spins to begin with, the bonus round selects a random symbol that appears as a stacked icon throughout the spins. What sets this slot apart, however, is that the free spins can be retriggered unlimited times. This could lead to massive payouts without paying if you get enough retriggers.  

9 Masks of Fire (Microgaming)

When it comes to modern graphics that dazzle and delight, 9 Masks of Fire may not be like other slots available today. However, this game by Gameburger Studios and Microgaming more than makes up for its more “classic” graphics with other features that make it one of the top slots to play.

The visuals use more old-school symbols such as cherries, sevens, diamonds, and the iconic bar symbol. These work well and make the game pretty straightforward, while the roaring flames surrounding the wheels add enough visual treat to satisfy your eyes.

A mask acts as a wild for all symbols and helps capture wins regardless of whether or not it falls in a particular pattern. For players looking to cash in, however, the shield symbol is what you want to see on screen. Getting three of these will trigger the free spin bonus round.

Once you do so, a large wheel will appear and begin spinning. Players will be awarded with 10 to 30 free spins depending on where it lands. Accompanying these are multipliers of up to three times. But during the bonus, these free spins can be retriggered an infinite number of times—something uncommon in other slots. 

Samurai Split (NextGen Gaming)

If you’re looking for games that offer unique gameplay and features, Samurai Split is among the best. The game is fully optimised for mobile devices, allowing you to play on the go. However, playing on a smaller screen doesn’t diminish the game’s outstanding graphics.

Featuring a watercolour backdrop of steep mountains and ancient Chinese buildings, the reels contain highly detailed symbols, including several unique Asian articles. The samurai themselves are crafted to show the strength and power behind the characters and make the icons stand out spectacularly.

One of the game’s best features are the spit symbols, which appear when a samurai jumps down and slices a symbol in half. Whenever this happens, it leads to better odds of a winning combination—and multipliers of up to 32 times. 

The free spin bonus, activated by receiving three or more scatters, grants between 5 and 15 free spins. However, should these scatters be split, up to 480 free spins can be awarded, giving you a serious chance to win big.  

Siberian Storm (IGT)

Starting life as one of the most popular brick-and-mortar casino slots in 2010, Siberian Storm was adapted to online play through a coalition between IGT and High 5. Fortunately, the online version is just as thrilling and offers the same gorgeous graphics as the original. Play this game and you’ll feel like you’re in Las Vegas taking a break from playing roulette or whatever table game has got its hooks into you.

The striking symbols in the game are carefully positioned in the uniquely configured reels, which range from three to five rows across the five reels. Wilds can appear in the three centre reels and massively help boost winnings. The centre reel is also where you want to see two or more tigers appear, as they trigger the free spin bonus.

During the eight free spins initially given, retriggers are possible. Getting enough of these can lead to more free spins, which are capped at a generous 240 before your bonus round ends. 

Cleopatra (IGT)

When it comes to Egyptian-themed slots, Cleopatra is something of a legend. This slot by IGT is one of the classic online slots deemed to never lose popularity among players and is featured in almost all online casinos—and for good reason. 

The game features stunning graphics that depict various characters, items, and artefacts from ancient Egypt. Chief among these is the legendary Queen Cleopatra herself. These symbols come to life in a colourful fashion that is accentuated by the game’s stunning animations.

While Cleopatra acts as a wild that substitutes for all symbols, the Sphinx represents the scatter. Getting three or more of these will trigger 15 free spins. These can be retriggered up to a maximum of 180 consecutive free spins. As a bonus, all wins achieved during free spins carry a triple multiplier that can further boost your payout.