Click or drag blocks to add their values to current sum. Match current sum to target sum to start a chain. The group of blocks used to make a sum will be marked. Make another group of blocks to match target sum. Repeat this process as fast as possible to keep the chain going. The chain will over once the blocks exploded. If any block touches the top border while the danger meter is full, the game is over. TIPS: 1) The more number of blocks used to match target sum, the higher the score multiplier; 2) the higher the danger meter when starting a chain, the higher the score multiplier.