This game falls into the “connect” genre where you try to link two matching tiles. It must be possible to “draw” a line between the two tiles, either by them being directly next to each other, or by there being empty space between them (the space around the outside of the playfield doesn’t count).
Click a tile and then click another tile with the same matching icon. If the two tiles can be “linked” or “connected” without any other tiles between them, they will be joined and removed from the playfield. Click the “Help” button within the game for further instructions.