A computer device provides a computer implemented game. A display displays game elements in a game board which has tiles. A first type of game element occupy two or more tiles and a second type of game element occupy one tile. The first type of game element has layers with each layer associated with a matching characteristic. A user interface detects user input when a user engages with a game element in a move. At least one processor determines that second game elements having at least one common matching characteristic satisfy a match condition and at least one of those second game elements is adjacent to a first game element. In response, it is determined if that first game element has a layer associated with the common matching characteristic, and if so, causes the layer associated with the common matching characteristic to be removed.