Circuit (Hardcore)

Circuit

Polluted Wasteland & Hardcore • Polluted Wasteland II

Sandbox Only Content

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Circuit (Hardcore) was previously removed on the 5th June 2026, though it has been made available through the Sandbox mode later.
It is not accessible anywhere else in the game. This page will attempt to include information about both the version before removal and its re-added version.

"Hello? Communicator's acting up...
This doesn't feel right, can you hea-RRrR"

―Commander dialogue on Wave 36 (Polluted Wasteland Fallen)

"ERROR: Incoming mysterious enemies!"

―Beginning of Wave 36 (Pre-Overhaul, Polluted Wasteland Fallen)

Description

The Circuit was a very fast enemy that appeared in Hardcore mode (it used to appear in Polluted Wasteland in Fallen mode, replacing the Error). Currently, it can only be spawned in Sandbox mode if the player has the Sandbox Plus+ gamepass. The Circuit has quite high speed and somewhat high health. However, the Circuit has the Super Charge ability, letting it make itself and surrounding enemies faster, including major bosses (like the Fallen King). If you are really unlucky, multiple Super Charges can stack, making strong enemies extremely fast, even faster than the Error and Glitch, making it a very dangerous enemy. The Circuit also has Stun Immunity, which makes the Warden and Electroshocker only slow it down and making knockback towers not knock it back.

The Circuit can be spawned from the Mystery upon its death in Hardcore mode, from wave 44 onwards.

Strategy

This strategy refers to the state of the game while the Invisible still appeared in the Hardcore mode.

• This enemy must be defeated quickly. If not, it can speed enemies up to speeds greater than the Glitch and Fallen Rusher.
  • This can speed up large enemies, such as the Slow King and Vindicator, and even major bosses like the Fallen King. Taking into account the ability to stack, this has the potential to be the most dangerous enemy in the game.
• Fast-firing towers, such as the Minigunner, paired with the Commander, are recommended to defeat the Circuit quickly.
  • Long range towers, like the Ranger, are also recommended.
  • The Accelerator is not recommended against the Circuit as it will likely get out of its range before the Accelerator can charge up.
    • Not to mention when the Accelerator targets an enemy it will not change targets before the enemy is killed, which may cause the Circuit to slip by.
    • You can counter this by slowing down the Circuit with the Frost Blaster, Toxic Gunner, Sledger, Harvester or Freezer to allow your Accelerators to charge up and attack it.
• The Rocketeer and Mortar can damage hordes of Circuits. However, be aware that the Circuit may outrun the projectiles from these towers.
• The Electroshocker, Toxic Gunner, Sledger, Harvester and Warden can be used to slow down the Circuit.
  • Do note that the Stun Immunity that the Circuit has prevents stunning towers like the Electroshocker from stunning it, with it only being slowed down instead and it cannot be knocked back because of it.
• The Military Base's Tank and Railgun Tank are the best in halting the advance of the Circuit as it can easily sprint past all of your defenses.

Gallery

Previous Variants

• 
  First version, first animation (29 April 2020 – 29 October 2020)
• 
  First version, second animation (29 October 2020 – 8 May 2021)

Corpse Variants

• 
  Second Corpse variant, current version (12 March 2025 – Present)

Miscellaneous

• 
  Circuit on its Index icon.

Trivia

• The Circuit, alongside the Speedy King, the Circuit from Polluted Wasteland II and the Commander enemy are the only enemies to make other enemies faster.
• The Circuit is the second (and currently only) Polluted Wasteland exclusive enemy to appear outside Polluted Wasteland.
  • The Rusher was the first enemy to appear outside it; it had a chance to be spawned from a Mystery when it died after wave 28 in Fallen mode. However, this no longer occurs.
  • Due to Polluted Wasteland being removed, the Circuit is the only Polluted Wasteland enemy to appear in the game.

Update History

• 29 April 2020 - Release v1.10.0
  • Circuit added.
  • Bug: Super Charge indicator disappears after 5 seconds.
  • Bug: Its ability can cause frozen enemies to start moving temporarily.
• 1 May 2020 - Release v1.10.0b
  • Bugfix: Super Charge indicator no longer disappears after 5 seconds.
• 29 October 2020 - Overhaul v1.0.0
  • Animation changed.
  • Partial Electric Immunity replaced with Energy Immunity.
• 8 May 2021 - Overhaul v1.3.0
  • Appearance changed.
  • No longer appears in Polluted Wasteland as it has been removed.
• 23 May 2023 - v1.7.3a
  • Energy Immunity replaced with Stun Immunity.
• 16 December 2024 - v1.46.0
  • Bug: Circuit appears twice in the Index.
• 5 June 2026 - v2.0.0
  • Circuit removed from the main game, as it has been directly replaced by Speedy King. Now appears exclusively in Sandbox mode.
  • No longer appears in the Index.

Fallen (Polluted Wasteland)
Previous Debut	Current Debut	Next Debut
Templar Wave 35	Circuit & Summoner Boss Wave 36	Fallen Hero Wave 39

Hardcore
Previous Debut	Current Debut	Next Debut
Error Wave 42	Circuit & Speedy King Wave 43	Molten Titan & Molten Boss Wave 44