How to play Color Merge, a SameGame-style puzzle

Neighbouring tiles (up, down, left, right) of the same colour fuse into one blob. Tap a blob of at least two tiles to remove it: it scores (n − 1)² × 10 for n tiles, plus the numbers printed on its tiles. Tiles above then fall and new tiles drop in from the top, so other blobs can meet and grow. The dark bomb tile is worth 50 and blasts the 3×3 tiles around it. Each stage has a target score and 20 moves: reach the target to move on to the next stage (500, 1500, 3000, …); run out of moves first and the game is over. The strategy: do not rush, and save one colour so it gathers into a giant blob.