Circuit Defender
Tower defense. Build a fixed grid path for bugs to travel from start to end. Click empty cells to spend bits and place firewall towers that auto-aim and shoot lasers at enemies. Endless waves with increasing difficulty. Offline-first, 100% client-side Vanilla JS with procedural Web Audio API sound effects.
Use Cases
Circuit Defender is a tower defense game built for quick strategy sessions. Players build a fixed grid path for bugs to travel from start to end, then click empty cells to spend bits and place firewall towers that auto-aim and shoot lasers at enemies. As waves progress, bugs become faster and tougher, testing your placement strategy and resource management. It is ideal for developers, students, and casual gamers who want a fast, tactics-focused break with no downloads, no accounts, and no network requests.
Because Circuit Defender runs entirely in the browser using the HTML5 Canvas API and procedural Web Audio API sound effects, it works offline, protects privacy by keeping all state local, and loads instantly on mobile and desktop alike — with zero external assets to download.
How-To
- Objective: Stop bugs from reaching the end of the grid path. Place firewall towers on empty cells to auto-aim and shoot lasers at bugs in range. Each bug destroyed earns bits and points; each bug that reaches the base damages your base health.
- Desktop controls: Click any empty grid cell to place a firewall tower (25 bits per tower). Towers automatically target and fire at the nearest bug within range.
- Mobile controls: Tap any empty grid cell to place a tower. The canvas scales responsively to fit your screen.
- Rules: Towers cannot be placed on the path cells. You start with 100 bits and earn 15 bits per bug killed plus a 25-bit wave completion bonus. Base health starts at 20 and drops by 5 per bug that escapes. When base health reaches zero, the game ends.
- Starting and restarting: Click Start Game to begin. After a session, the button becomes Retry to launch a new run. Use Reset to clear the current run without playing.
- Audio: Tower placement, laser firing, bug destruction, and base damage are generated procedurally via the Web Audio API. Click Mute to silence all sound.
Circuit Defender is a 100% client-side game built with Vanilla JS and the Canvas API. No server, no network, no uploads, and no external assets — play it anywhere, entirely offline.
Frequently Asked Questions
- Yes. Circuit Defender is completely free and requires no account, no subscription, and no in-app purchases.
- Yes. The game runs entirely in your browser using the HTML5 Canvas API, so once the page loads you can play it without an internet connection.
- Yes. Tap on empty grid cells to place towers. The canvas scales responsively to fit your screen on mobile Safari and Chrome.
- No. Circuit Defender does not store progress on a server. Your best wave reached is stored locally in your browser's localStorage for retention tracking.
- It is built with 100% client-side Vanilla JS and the Canvas API, with sound effects generated procedurally through the Web Audio API — zero external assets or dependencies.