Circuit Siege: Circuit Board Tower Defense
Circuit Siege is a free tower defense game that runs entirely in your browser. The map is a printed circuit board: data packets ride a copper trace toward the CPU core, and you build six kinds of tower — Pulse, Arc, Freeze, Mortar, Laser and Amplifier — on the empty board to stop them before they arrive. Click or tap an empty cell to build, press the number keys 1 through 6 to pick a tower, drag a tower out of the tray, and press Escape to deselect. The Standard campaign runs 20 waves with named bosses on waves 5, 10, 15 and 20, and every tower has three upgrade levels that show their exact stat change before you pay. Five difficulty tiers are listed below. The whole page weighs about 32 KB, no account is required, and it runs offline after the first load.
How to Play
- Pick a difficulty tier on the start screen. Standard is preselected; the five tiers and exactly what each one changes are listed again below.
- Choose a tower with the number keys 1 to 6, by clicking it in the tower tray, or by dragging it out of the tray onto the board.
- Click or tap any empty circuit-board cell to place it. Cells that the copper trace runs through are not buildable, and the range circle is shown while you aim.
- Watch the damage kinds. Kinetic (Pulse) is stopped cold by armor, energy (Arc, Freeze, Laser) shreds shields at nearly double rate but takes a penalty against armor, and explosive (Mortar) mostly ignores armor but is halved by shields.
- Select a placed tower to see its three upgrades. Each upgrade shows the exact stat change before you pay for it, and any tower can be sold back at your tier's refund rate.
- Set each tower's targeting priority to First, Strongest or Closest, and put an Amplifier next to your heavy hitters to raise their damage, fire rate and range.
- Read the next-wave preview panel before the wave marches. It names every packet type coming, how many of each, and whether they carry armor, shields or extra speed.
- Use the 1×, 2× and 3× speed buttons to fast-forward, and press Space or the Pause button to pause. You can still build and upgrade while paused. The Menu button opens the pause menu, where you can switch difficulty tier at any time.
- Press Escape to deselect. Every control is reachable with the Tab key, and the board itself can be driven with the arrow keys and Enter.
The five difficulty tiers
- Sprout — Made for young kids: packets that reach the core never end the game, towers cost half as much, and the next wave only starts when you press the button.
- Casual — The full 20-wave campaign with softer packets and a bigger cushion: enemies have three quarters of their health and you can leak five before the core falls.
- Standard — The game as designed: 20 waves, three lives, full-strength packets, and every armor, shield and speed variant in the pool.
- Brutal — Thirty waves against packets with 60% more health moving 15% faster, one life, a named boss every fifth wave, and selling a tower only returns half its cost.
- Inferno — Endless waves whose health compounds 13% every wave, one life, no wave-clear bonus so kills are your only income, and every tenth wave the packet pool gains a permanent random immunity.
Features
- Six towers with distinct jobs: Pulse (fast single target), Arc (chain lightning), Freeze (slow field), Mortar (splash), Laser (ramping damage on one target) and Amplifier (buffs every tower inside its aura).
- Three upgrade levels per tower, each showing the exact stat delta before purchase, and a sell button that refunds 70% on Standard.
- Packet variants that force mixed damage: armored Payloads and Blobs, shielded Crypts and Daemons, and fast Bursts and Swarms.
- Named bosses on waves 5, 10, 15 and 20 — NULL POINTER, RACE CONDITION, DEADLOCK and KERNEL PANIC — two of which split into smaller packets when they die.
- A next-wave preview panel that names every packet type, its count and its defenses before the wave marches.
- Five difficulty tiers from a no-fail-state Sprout mode for young kids to an endless Inferno ladder, with best scores tracked separately per tier.
- 1×, 2× and 3× speed control, and a pause that still lets you build and upgrade.
- Per-tower targeting priority (First, Strongest, Closest), hover range circles and floating damage numbers.
- Fully keyboard operable, honors prefers-reduced-motion, and stores nothing but four keys in your browser's own localStorage.
Frequently Asked Questions
Is Circuit Siege free, and do I need an account?
Circuit Siege is completely free and there is no account, no sign-up and no download. The game is a single static page: open the URL and it starts. There is no backend and no database behind it, so there is nothing to log in to. After the first load the page is cached by your browser and the game runs offline.
Which difficulty should I pick?
Standard is preselected and is the game as designed: 20 waves, three lives and every packet variant. Sprout is built for young kids and has no fail state at all, so a packet reaching the core never ends the run. Casual keeps all 20 waves but gives you five lives and weaker packets. Brutal is 30 waves with one life. Inferno never ends, pays no wave-clear bonus and hands the packet pool a new permanent immunity every ten waves. You can switch tiers from the pause menu at any time, and your best result is tracked separately for each tier.
How do the towers and damage types work?
There are six towers and three damage kinds. Pulse deals kinetic damage, which is fast and cheap but has the packet's full armor value subtracted from every hit. Arc, Freeze and Laser deal energy damage, which drains shields at nearly double rate but takes a 30% penalty against armor. Mortar deals explosive damage, which mostly ignores armor and hits everything in a splash radius but is halved by shields. Amplifier fires nothing and instead raises the damage, fire rate and range of every tower inside its aura. Because no single kind beats every defense, a working board mixes at least two of them.
What does the game store about me?
Four values, all in your own browser's localStorage and none of them personal: your selected difficulty tier, your total number of runs, your best score per tier and your highest wave reached per tier. Nothing is uploaded, there is no account and no personal data is collected or transmitted. Clearing your browser storage erases all of it, and the privacy page lists the exact key names.
How was this game made?
Circuit Siege was generated from a single prompt by Quodara, an AI agent platform that turns a prompt into a deployed web app, and it was built and deployed without a human writing the code by hand. The whole game is drawn with the browser's 2D canvas API, with no game engine and no third-party runtime dependencies. The full write-up, including the prompt that produced it, is on the Quodara case page at quodara-ai.com/showcase/circuit-siege.
About this build
This entire game was generated from a single prompt on Quodara, an AI agent platform that turns one prompt into a deployed web app, and it was built on 2026-08-21. The finished page weighs roughly 32 KB transferred on a first load, of which about 22 KB is gzipped JavaScript — there is no game engine, no sprite sheet and no third-party runtime dependency, because every pixel is drawn with the 2D canvas API. The full build write-up lives on the case page at quodara-ai.com/showcase/circuit-siege.