History
The Aliens are the main enemies of the fishes, as they enjoy the taste of their meat and will actively hunt them, prompting the player to defend the tank against them and try to save every aquarium of the world in the progress by defeating the mastermind behind the invasion. The original online game had only four aliens, but the final, deluxe version adds other four more, including the final boss, Cyrax. After their defeat, the aliens redeem themselves by making peace with the fishes and decide to leave Earth's aquariums alone.
Types of Aliens
Sylvester
The very first alien the player encounters. He's also the weakest of them. Sylvester will swim around the tank, but he can only eat one fish. He is blue with long, sharp teeth, claws, a tail, no feet, no visible eyes, and long arms. Players can defeat him pretty easily. He was modeled after a Xenomorph. He only spawns in the first tank and in the final battle.
Balrog
A demonic alien who resembles a cross between a merman and a lion. He's the second alien the player faces and will spawn on every tank. He is stronger than Sylvester and can eat every fish quite fast, but is still not much of a threat. In the 4th tank, He is paired up with Psychosquid.
Gus
A fat alien, Gus is in fact a strange creature called "Baby-faced man-child". He is inmune to lasers and can only be destroyed by overfeeding him with fish food until he explodes. Anything edible can damage him. Oddly enough, your lasers are able to hurt him in the final battle.
Destructor
An evil robot that is the fourth alien encountered. Destructor doesn't eat fish but will fire heat-seeking missiles at them to kill them.Thankfully, Destructor is confined to the bottom of the tank, and the player must destroy its missiles before they reach any fish. In the 4th tank, it is paired up with Ulysses,.
Psychosquid
One of the most difficult enemies in the game, Psychosquid is a monstrous cephalopod who can eat multiple fishes and is armed with a butcher's knife, a fly swatter, and a fork. He can enter in a dormant state after being shot for some time, in which he drops his tentacles and becomes blue. If the player shoots him in this phase, he'll regain health instead of being damaged.
Ulysses
A cyclops-golem like alien who will fire energy balls at your fishes. The energy balls can't be destroyed, but can be deflected back at Ulysses, damaging him. The energy balls are more dangerous when deflected because they could kill any fish in their way. Much like Destructor,Ulysses spawns only in the tank's ground. In the 4th tank, He is paired up with Destructor.
Bilaterus
The second most difficult enemy, Bilaterus in an animated serpentine skeleton with two heads, one fish-like and other reptile-like. He's able to eat multiple fishes and shooting any part of its body, including its spine, can hurt them. The player must destroy its two skulls to kill him.
Cyrax
The final boss and evil mastermind behind the invasion, Cyrax is a cephalopod-like alien. He will summon several of the aliens you've encountered before and Mini-Sylvesters. He is the strongest alien and has the highest health. Despite that, he cannot hurt anybody directly, but will summon his henchmen to do the job.
Mini-Sylvester
An alien that only appears in the final battle to aid Cyrax. They are basically miniaturized clones of Sylvester.
