In an Air Based attack, it’s best to try to destroy as many Archer Towers early on in your attack.
Clash of Clans Archer Tower Upgrade Differences
When initially constructed, the Archer Tower has an open wooden lattice supporting a flat wooden platform; an exterior wooden ladder leads from the ground to the platform level. From levels 2 through 5, the lattice structure and wooden platform both receive additional reinforcement. The Archer Tower has two Archers on its platform, with the appearance of a level 1 (or 2) Archer, and shoots normal arrows.
At level 2, the Archer Tower gets 4 short posts on the top and the wood gets thicker.
At level 3, the Archer Tower gets gray stone paddings on the legs and the short posts connect each other on the platform.
At level 4, the Archer Tower has the paddings turn into supports and a small green flag is added under the platform. The Archers on its platform start to shoot flaming arrows.
At level 5, the Archer Tower gets a solid stone base which connects each support. The Archers on its platform now has an appearance of a level 3 (or 4) Archer.
At level 6, the lattice supports and exterior ladder are removed, and solid vertical supports are added. The wooden platform receives stone battlements and the green flag is extended to cover the interior.
At level 7, the stone battlements around the platform are reinforced and the solid stone base is taller to completely obscure the interior. A third Archer appears on the platform and they start shooting purple arrows.
At level 8, the Archer Tower receives metal braces at the bottom of each leg. The Archers on its platform now has an appearance of a level 5 Archer.
At level 9, the Archer Tower’s flags get shorter to reveal the interior again and the metal on each leg turns into spikes.
At level 10, the flags get larger again, golden plates get placed around the whole tower and the wooden supports gets darker. Arrows shot by the Archers now explode on impact.
At level 11, the color scheme completely changes as all the wood is replaced with dark iron, and the battlements receive dark iron shields on each corner with stone skulls in between them. The flag changes from green to orange. The Archers on its platform now has an appearance of a level 6 Archer and they shooting flaming arrows.
At level 12, the tower gains golden guard shields on its bottom and golden spikes all over it with silver corners at the top. The flag is replaced with spikes and the battlement walls become highly polished metal. The archers shoot with fire arrows. The planks where the Archers stand also switch directions.
At level 13, the 3 golden guard shields fuse together into 2, becoming thicker and the silver plating on the top becomes golden instead. The plating the lower spikes are attached to become a deep crimson, and the corner shields themselves turn red. The tower also gains a gold colored base at each leg and a lighter hue on the wood on top. The Archers on its platform now has an appearance of a level 7 Archer and they shooting flaming reddish-pink arrows.