Tidalis

Tidalis is a puzzle game where the player has to use streams to match blocks of the same colour. This is called a chain reaction. Each block has an arrow on it which decides what direction the flow will go. By clicking on a block the player starts a stream which flows through all blocks in its range (three spaces) of the same colour. After creating a chain reaction the blocks will be removed from the screen. Blocks come in different colours and a stream can travel through blocks of other colours than the starting one without any effect. Blocks can't be moved but they can be rotated so that their arrow direction changes. When blocks are removed from the screens other blocks will fall down and take their place. Falling blocks will send out new streams when they land and therefore it's possible to create combos (several chain reactions in a row). More blocks fall from the top of the screen and the player has to clear them out so that they don't reach the top. If they do the player will lose. The criteria for success differs from level to level. Most common is to clear a number of blocks or to survive for a set time.

Tidalis comes with several game modes of different kinds with both action and puzzle based gameplay. The adventure mode features a story where the player travels through the land of Tidalis and 115 levels. The player can choose to skip a level and it will then return later. The adventure mode is action based and plays as described above. Action based levels can also be played in the quick game mode where the player can customize the game in a number of ways such as difficulty, rules and game styles. For a more puzzle based gameplay the player can try to solve brainteasers which lack the time limits of the action based levels. The player can also create his own custom games where he chooses from a large amount of settings and include only the game styles that he finds interesting.

The game also features a number of multiplayer game modes. Offline it can be played by up to three players either on one or two game boards. Two-player mode is the same as the single-player mode but with one player controlling the mouse and the other the keyboard. There is some limitations with this however since the players can't compete against each other. To do so two boards are needed. Over network the game can be played by up to six players on two computers. Both co-op and versus modes are available. In multiplayer it's possible to apply handicaps to the players. This allows players of different skill to compete or contribute on the same level.