Aquarium

Aquarium is a falling block puzzle game with an underwater theme. At the start there is a character choice of eight underwater animals such as a dolphin, a shark, a turtle or a jellyfish. Blocks are formed as a line of three fishes of different types and colours. They drop down from the top of the screen and the next block is shown in a preview window. The player can move the block left or right and rotate it. The order of the fish inside block cannot be changed. The blocks stack and open spaces are filled up. The goal is to create matches by linking three or more identical fish to make them disappear. This can be done in a combination of shapes where the fish touch horizontally, vertically or diagonally. When a match is made the fish disappear, points are scored and the open spaces are filled up again. Sometimes multiple matches in succession can be formed through a combo.

Not all fish can be matched in this way. Some fish are encased in bubbles and some pieces contain an empty bubble. When a possible match contains a fish inside a bubble no link will be made. The bubbles only disappear for pieces that touch the link when a match is made. Sometimes pink aqua bubbles appear inside blocks and these can also be collected through matches. Here the chosen character comes into play. Each animal has four special attacks (requiring one, two, three or four aqua bubbles) that can be used to hinder the opponent. Examples include making the blocks drop slower or faster, a color attack, obscuring the field in black ink, freezing the screen and so on. Aqua bubbles can be collected to use them at an opportune moment.

Ice is another gameplay element. When a match is made cubes of ice drop down automatically in the opponent's field for the same amount of pieces inside the match. Ice cubes just take up space. They can be removed by creating a match next to them or by waiting, as they gradually melt and eventually disappear, creating room again. The game is not necessarily lost when the field is completely filled, there is also a win condition based on the points even if the opponent is still alive. The game can be played single-player, defeating the computer-controlled opponents one by one, or against another player. There are two control mechanics.