Best Alien Slot Games Online: Ready to Fight the Invasion?

The best alien slots online combine the best parts of sci-fi with the excitement of modern slot games. In addition to showcasing fascinating alien creatures, these titles are also loaded with great bonus features and offer an excellent experience.

I highlight my favorite alien slot games available online below. Before I dive into their features and gameplay mechanics, here’s a quick overview.

Best Aline Slots Online (Overview)

Ally Alien

Ally Alien from DiceLab is another great example of the best that online alien slots have to offer. The game is set in outer space and features multiple aliens and planets as its symbols. It offers similar bonus features to Alien Spinvasion, including free spins and unique wild symbols.

The wild symbols in Ally Alien can replace any other symbol in the game. They are especially useful during the collapsing wins feature. If you can land four or more collapsing wins in a row, you will activate the free spins mode and receive a prize multiplier.

There are six combinations of free spins and multipliers up for grabs in this alien slot machine. The most free spins you can win at a time is 50, and you can retrigger free spins endlessly. If you trigger the top prize with nine collapsing wins in a row, then you have a chance to win a 2500x multiplier.

You can test your luck in Ally Aliens at Red Dog Casino. It offers a free demo of the game and has a paid version as well. New members of Red Dog can choose from multiple welcome bonuses, including a 275% crypto bonus worth up to $2,750.

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Alien Fruits

Alien Fruits is a 6×5 slot game that is both a great alien slot and a great fruit slot. It was developed by BGaming and has an RTP of 96.03%. This slot has a larger grid than other games on my list and uses a cluster pays system instead of traditional pay lines.

You can also trigger the free spins round for free during the base game if four or more scatters appear on the board. Additional scatters that appear during free spins can retrigger the feature. There is also a buy feature, so you can trigger the free spins mode at any time.

In addition to the free spins mode, Alien Fruits also makes it easy to win massive prizes. It has an exciting multiplier feature that appears during the free spins. The multiplier symbols offer a random multiplier between 2x and 100x your stake amount.

There are free and paid versions of Alien Fruits available online at Bovada Casino. New members of this site are eligible for one of two casino welcome bonuses, including a 375% crypto bonus worth up to $3,750.

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Back to Venus

It Came From Venus by Betsoft was a popular alien slot game in the mid-2010s. Back to Venus, the sequel, offers the same excitement as the original, with a higher RTP. The original game had an RTP of 95.80%, and the sequel has a return of 97.07%.

An increased RTP is not the only advantage the sequel has over the original. The hit rate, for example, has also been increased from a below-average 10.08% to an above-average 45.28%.

Back to Venus has plenty of bonus features, too, including sticky wilds that stay on the reels for two additional spins. There is a free spins mode as well that you can activate with the rocket bonus symbol. Losing spins can quickly become profitable, too, if you randomly trigger a respin with the stick and respin feature.

If you want to try the Back to Venus slot game today, then you should sign up for an account at Ignition Casino. It offers a free demo and an exciting paid version of the slot. New members can get up to $1,500 in bonus casino funds with the crypto welcome bonus.

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Vegas Space Heist

Vegas Space Heist combines alien life forms with the glitz and glamour of Sin City. The slot was released by Qora Games in 2025, making it one of the newest alien slots on my list. It has an RTP of 96.09% and uses 720 pay ways.

You need at least three matching symbols on adjacent lines to earn a payout in this 3-4-5-4-3 slot. Also, wins are awarded from both left-to-right and right-to-left.

There is a wild alien symbol that appears on the middle three reels in Vegas Space Heist. It replaces every symbol except the Money bonus symbol. Also, combinations that use wilds are guaranteed to reward you with the highest possible payout.

Vegas Space Heist also uses special coin symbols that you can collect during the base game. Any UFO that collects a coin symbol has a chance to trigger the Jackpot Radar mini game. During the bonus round, you can win one of five fixed jackpots, including a grand prize worth 1,000x your stake amount. 

SlotsandCasino is the best site for playing Vegas Space Heist for free today. It offers a free-to-play demo, as well as a real money version of this alien slot. Every new member who makes a qualifying deposit can claim a crypto welcome match of 500% worth up to $2,500.

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Nebula Jackpot

Nebula Jackpot from DiceLab also uses 4096 pay ways instead of pay lines. It pays left-to-right, and you need at least three matching symbols on adjacent paylines to create a winning combo. The game has an RTP of 96.00% and uses a 6×4 grid.

The galaxy symbol acts as a wild in Nebula Jackpot, substituting for every symbol other than the scatter. Speaking of the scatter, this bonus symbol can trigger up to 100 free spins. 

You need at least three scatters to trigger the bonus feature, and the more scatters that trigger free spins, the more spins you will get. Any scatters that appear during free spins will add more spins to your remaining total. Nebula Jackpot does not put a limit on the number of free spins you can trigger during the feature.

Wilds are upgraded during free spins, too. Any wilds that appear on reels two through six can have up to a 3x multiplier. If multiple wilds appear on the same line, their multipliers are added together to create even bigger wins.

You can experience all the fun of Nebula Jackpots for free today at El Royale Casino. The casino also offers a paid version of this exciting alien-themed slot machine. New members who qualify for the VIP welcome bonus can get up to $23,000 in extra slot funds.

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