On level 16 you need to break the chains on the sides to get to the inaccessible golden tiles. There are three chains on each side, and the task may seem quite hard. However, if you look closely, you will notice that some of the chained pieces are of the same color. All you need is to charge a single Lightning power-up. Use it to destroy those pieces, and you’ll be all set!
Keep a close eye on the field as it is essential that you do not miss a chance to create more power-ups! Do not rush into using them though – try to get a couple of power-ups close to each other and explode them in a single move. This will clear more space and will charge the Lightning power-up faster.