Bovine-based slot play is nothing new to casino-goers, but Invaders Attack from the Planet Moolah is definitely more bizarro than Buffalo.
Invaders Attack from the Planet Moolah, in fact all Planet Moolah slots, are perhaps the ultimate in slots acquired taste. I have spoken to many slots players about them, and generally the consensus is divided pretty evenly in three ways: people who love them, people who hate them, and people who are just outright confused by them.
I must admit that I was the latter for a long while. I am one of these people in life who gets immensely stressed by chaos. And, make no mistake about it, to the untrained eye, Planet Moolah slot games are total undeniable confusing chaos, a malaise of madness.
There are spaceships hovering around, there are cows in the cockpits. There are trailer park hicks throwing around their possessions. There is a dog called Rufus, and a unicow. What’s a unicow? Ah the mythical unicow. Some say it doesn’t exist, some say it appears only to those who believe, others see it and still don’t believe it, like Scrooge telling Marley’s ghost he was an undigested piece of food.
And yet… and yet… we all want the unicow. As slots players, we crave a liaison with the unicow like teenage girls in the 1990s craved one with Keanu Reeves.
Anyway, let us dive deeper into the brilliant madness of Planet Moolah, which was actually the second in the series but most popular. You want to play it, I promise you that. You just don’t know why yet.


If you had to choose one word to sum up Invaders Attack from the Planet Moolah, then it would be loud. It’s incredibly loud. Light and Wonder appear to have given all of their Moolah game cabinets just two volume settings: silent and ears-splitting.
That is, though, a big part of its charm I think. Invaders Attack from the Planet Moolah is right in your face by design. It’s loud, bright, and crazy.
The theme is actually quite a simple one. Aliens have come to earth in their spaceships, but not to see humans. In fact, humans are a bit of an inconvenience if truth be told. They have returned to get their cows back, because it turns out that cows are from the Planet Moolah. I am unsure on the lineage of the story, if truth be told.
Did cows originate on Planet Moolah come to earth, crash land, send out a distress call across the cosmos, and those arriving now are the rescue party? Or did cows evolve on earth and crack space travel before humans realised how delicious they are, and are fleeing to the stars in search of a new home?
I don’t know. But what I do know is that they really want their cows back now. They hover above the reels in their UFOs and any time a cow symbol (which happens to be the Wild) lands, they beam them up like in Star Trek. You want that to happen, though, because the bonus is triggered by cascade wins and Wilds really help that happen.
The overall design of this space-themed slot is very good and very engaging. It’s cartoony with bright colors and fun characters, and there is plenty to look at on the screen between and during spins. The sounds are great too, with each cow having its own distinct ‘moo’ voice.
Let’s be real here. The only difference between a fun slot machine and a frustrating slot machine is whether or not you win. That has always been the case.
However, the first thing you have to do when you pull up a chair at Invaders from the Planet Moolah is brace yourself for a massive amount of frustration.
That is entirely down to the bonus trigger mechanic. Invaders from the Planet Moolah slot machine does not have bonus symbols, you see. It’s not like, for example, Dragon Link, where you know that any one spin can give you three free game scatters or six hold and spin balls. If only it was that simple.
In Invaders from the Planet Moolah, you trigger the bonus by getting at least four cascade wins in row. You hit spin, and any winning line pays before being zapped clear by the cow-piloted spaceships. Yes, that’s an actual sentence. Bear with me.
When they are zapped new symbols drop into their place, and if they form winning paylines too, the process repeats. Do it four times and you get seven free games. Do it more than four and the number of games goes up with each successive cascade win.
Often, far too often, that cascade win streak ends at three. That’s fine for the first few times, but the anguish can build quickly when it keeps happening. I have seen many a casino-goer bordering on insanity playing Planet Moolah games, which in fairness is very much in the spirit of the game.
You can get very good line-hits along the way too, though, especially when the Wilds line up. So don’t think that it’s a bonus or bust kind of game. At the same time, though, accept that madness may find you before you start spinning.
At a glance:
The bonus feature is… complicated. Oh boy, how do I explain it? Let me give it a try!
Well, first off you know that you need at least four cascade wins to trigger it. That is the simple version.
Remember those Wilds I told you about? Some have special features attached, like reel blasts, double games, and credit amounts. If you collect those symbols during the cascade wins that trigger the Free Games, those features will be applied to the Free Games. That’s the first complicated thing.
Then, before the Free Games start you will get a wheel feature. A large UFO will appear and spin, and you will land on a special type of feature. They include giant symbols, multiplying wilds and ‘we want our cows back’ which will involve locals throwing things at the UFOs to drop cows back into the reels that then act as wilds.
As if that wasn’t enough, you will then get a secondary wheel. That can initiate a blast that gets you off to a great winning start in the Free Games, or a mini-feature that can win you credits – including a Progressive Jackpot.
Is everyone clear? Probably not. So here is a video of the game in action.
Okay, let’s deal with this unicow issue. Basically, you want the unicow. It’s the reason most people put up with the frustration and confusion of everything that is Invaders Attack from the Planet Moolah.
The unicow is rarely spotted, but it is essentially just a Wild. A Wild that is a cross between a unicorn and a cow, but a Wild still the same. I promise I am not making this up.
If you collect that during the cascade wins that trigger the Free Games, you will be awarded ALL special Wild features immediately that are then queued to be used when needed. That keeps the cascade wins going and the more cascades you have, the more free games you win.
So, generally, if you find the mythical unicow whilst triggering the Free Games, you’d better have a drink handy as you are going to be looking at literally hundreds of free games. And now you know why people play this maddeningly brilliant slot machine.
As with all slot machines, if you are playing Invaders Attack from the Planet Moolah, make sure your player rewards card is in the machine. It’s actually quite a good game for building points as the line wins can help you recycle money and play for longer.
And, as always, make sure you keep an eye out for your waitress. Most land-based casinos in the US, especially those in Las Vegas, will offer you complimentary drinks whilst playing. Order what you want but make sure you tip your waitress if you want them to come back again. Some places, like many casinos in Atlantic City, have drinks available to order on the machine itself based on your play, so keep your eye out for that as well.
There are some slot machines that you just know everyone is going to love. Everyone has a favourite Buffalo for example. It’s unlikely you will find anyone who doesn’t love to play on Dragon Link or Lightning Link. Mo Mo Mo Mummy is the latest to grab the attention of players and most still love Huff N’ Puff, even if they are slowly getting more difficult to like.
Invaders Attack from the Planet Moolah is not like those slot machines. I can’t tell you if you’re going to love it or hate it. I just know it’ll almost certainly be one of them.
What I can tell you, though, is that you will notice it. You will also remember it and, one way or another, after you play it you will think about it again – and again, and again. Whether those thoughts are loving or pure unbridled cogent thought-crushing frustration is anyone’s guess, but it’s certainly memorable.
Lynsey is a regular Las Vegas visitor and a keen slots and roulette player. As well as significant experience as a writer in the iGaming and gambling industries as an expert reviewer and journalist, Lynsey is one half of the popular Las Vegas YouTube Channel and Podcast 'Begas Vaby’. When she is not in Las Vegas or wishing she was in Las Vegas, Lynsey can usually be found pursuing her other two main interests of sports and theatre.
Read Full BioInvaders Attack from the Planet Moolah was developed by WMS (Williams Interactive), now part of Light & Wonder. It’s part of the long-running “Moolah” franchise, known for its quirky alien theme and entertaining bonus mechanics, making it one of WMS’s most recognizable and successful slot series worldwide.
At present, Invaders Attack from the Planet Moolah is mostly found in land-based casinos. There’s no official real-money online version, although you can find it online in some territories, as well as earlier titles in the series.
You can play Invaders Attack from the Planet Moolah in casinos across North America, Australia, and Asia, especially in top destinations like Las Vegas and Macau. It’s a popular WMS title frequently featured in modern gaming lounges and progressive banks across major casino floors.
Yes. The game’s main feature is its Cascading Reels system, where consecutive wins trigger new symbol drops and potential Free Spins rounds. Each consecutive cascade increases rewards, and bonus spins include special wilds and enhanced multipliers.
The Invaders Attack from the Planet Moolah Classic slot has an average Return to Player (RTP) of between 85 - 95%. However, the exact percentage may vary slightly depending on the casino, local gaming regulations, and machine configuration, which is a common practice with most land-based slot installations.
Invaders Attack from the Planet Moolah was released by WMS (now Light & Wonder) around 2019–2020 as a sequel to the classic Invaders from the Planet Moolah (2008). The updated version introduced modern graphics, dynamic animations, and expanded free spin bonuses while keeping the franchise’s signature alien-meets-cow humour.
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