Easier difficulty
Place your device on a stable surface and enlist the help of a friend. Have one person responsible for the top lane and the other for the bottom line. You still need precise timing, but will have less pressure to react quickly.
Timing
There are various types of cars and the more bombs will be required to explode them the farther you get. However, the bombs have different movement speeds, making it important that you always tap at the precise moment. Sometimes the first bomb that appears will not be the first to explode; sometimes you must tap two or three times.