Nightmare Fuel / Insaniquarium

• The alien attacks can be quite scary for young players. You're minding your own business, feeding your fish and collecting money, when suddenly the claxon blows, the music turns ominous, and with a roar, an alien appears.
  • The "Alien Approaching/Alien Battle" theme is incredibly chilling, especially for a game as innocent looking as this. It sounds like something directly from a slasher film.
  • Psychosquid really lives up to his name. He's a big, red squid with dangerous weapons in his tentacles, and eats fish much faster than anything else in the game.
• The ending to 4-5, the level before the Final Boss. The Presto egg is shown where the egg hatching animation plays like normal... only for Cyrax to appear with loud, evil laughter which stops the Presto egg from hatching. Turns out that you have to complete the next tank (Tank 5) with at least one pet alive and defeat Cyrax to get the Presto egg!
  • Said Final Boss, for that matter. Your pets are all dropped into an eerie tank, and Cyrax appears not long after. None of your pets can do anything to fight him, and the aliens can eat them. Going through the entire game knowing your pets are safe from aliens just to find out that they're at risk in the end is horrifying.