From Worms Knowledge Base
As if Alien Abduction wasn't enough, the aliens are back with a new idea in their over-sized possibly transparent heads. And their intentions aren't peaceful. Not that they were before.
Having got out his trans-galactic homing beacon when this weapon is selected, your worm is about to invite some Greys over for tea. Or not. Upon activation, several UFOs are on the scene, randomly zapping the landscape from all directions with lasers, plasma cannons and, for those trekkies out there, quantum torpedoes as they hover above, causing small but ubiquitous craters in the landscape. When they've finished their fun, they go back home.
The technical issues concerning the UFOs directly here are covered in the article for the Alien Abduction weapon. Each ship should be fixed with a form of weapon with a nifty animation allowing them to destroy the landscape.
This one surely counts as a super weapon, as it affects the whole landscape. Actually, that isn't strictly true, as subterrainean worms would most likely be safe from the zapping on the surface. Still, this weapon resembles a powered-down version of the Armageddon, a weapon seen as pointless by many for it's excessive destructiveness. The Alien Invasion would make a good replacement for the Armageddon.
This would most likely be considered a darkside weapon due to ability to call in the Alien Invasion from underground, without risk of damage to or exposure of tunnelling worms.
Everything aesthetic about this weapon is covered in the Alien Abduction article. Generally, this would fit well into the Worms environment.