Constructor (Boss)

Constructor
First appears in level	3.8 (Wave 50)

Moves at a speed of 0.65 t/s. Every five seconds, creates one Regular, one Fast, and oneStrong enemy, while becoming invincible.

Constructor will also create additional enemies and become invincible when it's health reaches certain amounts, those being three enemies at 75%, five at 50%, and seven at 25%. The enemies Constructor spawns here are randomly selected from the list of enemies that can appear in the level, plus the three types mentioned above even if they are not present.

Constructor deals 100 points of damage to the base, which usually ends the game immediately.

Strategy

Constructor is one of the hardest bosses to deal with, due to its invulnerability frames and immunity to crowd control effects. It is critical to eliminate this boss as quickly as possible, since Constructor will spawn more enemies, the longer it stays alive. Sniper is a great choice against Constructor, being a dedicated single target tower. If the map is small enough, Minigun can deal far greater damage. Like other bosses, it takes 90% less damage from abilities. Ball lightning's damage is further reduced by another 90%, resulting in a pathetic 1% of its normal damage output. Using abilities against Constructor is generally ill-advised, as they cannot outlast or skip the invulnerability frames.

Bugs

• Due to the randomness of enemies spawned by Constructor, the levels featuring this boss used to suffer synchronization issues, causing the score visible on the leaderboards to differ from the score gained by the player.