How do you make mega towers in Bubble Tanks Tower Defense?

In Bubble Tanks Tower Defense, to create mega towers, you need to combine several smaller towers. Start by selecting a tower that you want to upgrade and then drag and drop it onto another tower of the same type. This merging process will produce a more powerful mega tower, which has enhanced capabilities and can cover a larger area. Keep repeating this with additional towers to create even stronger mega towers as you progress through the game.