Invaders Megaways Slot by Light & Wonder

Every base spin starts with a UFO sweeping in to pick one paying symbol at random, and every copy of that symbol on reels two through five turns wild for the rest of the spin. It is the move that defines the game. You watch the saucer hover, it tags a cow or a ray-gun alien or a card royal, and suddenly the board is stacked with substitutes before a single win is even scored. Wins then explode and drop fresh symbols in from above, the horizontal top reel refilling from the right, and the cascades chain until nothing new lands.

The other base trick is the Mythical Unicow. On any spin it can show up and stretch every reel to between seven and ten symbols tall, pushing the ways count up toward the ceiling. The reels normally run two to ten symbols each across six columns plus that top strip, so a Unicow appearance turns an ordinary grid into a wall of symbols and far more ways to win.

Four orange BONUS planets open the free games at seven spins, five gets you ten, six or more hands over fifteen, and three landing inside the round retrigger more. Two things compound in there. A win multiplier ticks up by one with every cascade and never resets, so a long chain late in the round can run the figure high. On top of that, each free spin rolls one of five wild modifiers at random. Logo expands the green INVADERS logos to fill their reels. Scientist turns the bald mad scientists wild and doubles that running multiplier on every cascade instead of adding one. Alien grows reel heights for more ways. Cow makes the abducted cows count as double wilds. Ray Gun simply drops an extra wild onto the board for each gun showing. You never know which you will get, and the Scientist roll layered over a big cascade chain is the one everyone hopes for.

The whole thing plays out over a nighttime farm with green saucers tractor-beaming cattle into the sky, a starry backdrop and a glowing blue horizon, the symbols all neon-edged in green, magenta and orange. It is a comedy alien invasion sat on Big Time Gaming's Megaways engine, dressed up by Light & Wonder, with no jackpot and nothing to buy your way into the bonus.