The Aquarium is a city facility containing 5 separate slot machines which allow players to gamble for items or upgrades.
Four of the machines (Starlight Slots, Fantasy Globes, Weapon Machine, and Mystery Machine) are playable using special Tokens. With the exception of the Mystery Machine (which uses Mystery Tokens that can be created at the Factory}, the tokens used to play the machines are purchasable at the Cash Shop.
The fifth machine however (the Gamble Machine) uses weapon and armour Gamble Cards to apply suffix/prefix bonuses to the player's weapons and armour, which plays a very important role in upgrading a player's equipment
The Gamble Machine allows players to add Prefix or Suffix enhancements to their armour and weapons, using Weapon or Armour Gamble Cards. After placing a weapon or armour in the slot, the player may include up to 1 Prefix Card and 1 Suffix Card to gamble with. Only one Prefix or Suffix may be applied to an armour or weapon at a time, and if a weapon or armour already has a Prefix or Suffix attached, it must be removed before another one can be applied.
Starlight Slots uses "generic" (gold) Tokens purchased at the Cash Shop. It has the potential to award the player armours, including the rare Zodiac (Cash Shop) armours, though winning an armour is not guaranteed.
Fantasy Globes uses Heart Tokens, purchased at the Cash Shop. It rewards the player with a randomly selected "globe", which contains a cache of items (such as Gamble Cards).
The Weapon Machine uses Weapon Machine Tokens, purchased at the Cash Shop. It has the potential to award the player a randomly-selected weapon (including rare weapons which are available only through the Weapon Machine)
The Mystery Machine uses Mystery Tokens, which can be created at the Factory - it awards the player with a variety of randomly selected items (such as Energy or Shield Kits).