On level 56 it’s recommended to spend your first moves destroying the crates (i.e. horizontal matches for the bottom crates and vertical ones for the side crates). At the beginning you should concentrate on destroying the obstacles instead of collecting small power-ups such as firecrackers. However, if you can collect bigger power-ups, you shouldn’t ignore them as they will help you destroy even more crates.
As a result, by concentrating on clearing the game field, you will get a vast open space for collecting stronger power-ups, which will very likely lead you to success in passing the level.