Cybershock : TD Idle & Merge for Android
The game has pretensions to have a cyber punk style, and the towers look like combat robots if you choose them. However, they are shown schematically on the playing field, and the field itself looks like a labyrinth of zones with a field to merge the towers in the center.
The player gets money for killed mobs for which he can buy regular towers, which appear on the field. To get a tower of a higher class, they must be merged, and then you will get a more powerful tower made of two regular ones. There is a system of boosters and power-ups.