The core of the game is to link at least 7 cells of the same color orthogonally (horizontally and/or vertically). When you link 7 or more cells, they disappear, like this:
At the start of the game/level, 3 pieces appear in the bottom. When you place the last of these 3 pieces on the board, 3 new pieces appear.
It is not possible to rotate or flip a piece. This is by design: if this was possible, there would be so many possibilities to orientate and place the three pieces, that the game would take much longer.
There is also a holding area, where you can store a single piece that you don't want to use right now:
There are 3 difficulties: Easy, Normal and Hard. The main difference between them is the board size: in Easy mode, the board is 10x10; Normal is 9x9; and Hard is 8x8.
When you first open the game, only Adventure Easy mode is available. There are several unlocks available:
In Adventure mode, you start at level 1. Each level has one or more goals to complete, for example:
The fewer moves you need to complete all goals, the more stars you get when completing the level.
In Endless mode, you get points for each clear you make. The more cells you clear with a single move, the more points you get. The game ends when no legal move is possible. Your goal is to score as many points as you can.
Endless mode also has a bonus item shop.
When you earn enough points, you level up. When you level up, or when you clear a large amount of cells in 1 move, you gain coins. With coins, you can buy bonus items in the shop. The bonus items are: