🚀

ArcadeOwl Retro Arcade

Citadel Defense 21

Blanket the sky and keep every city standing through the barrage.

What is it?

Citadel Defense 21 is built for quick, satisfying sessions that load in a heartbeat. Blanket the sky and keep every city standing through the barrage.

How to play

• Falling missiles streak down from the top toward your cities along the ground.
• Tap a spot in the sky to set off a defensive blast there.
• Any incoming missile that passes through your blast is destroyed before it lands.
• Lose a city every time a missile gets through — protect them all.

Why you'll love it

• Free to play instantly — no download or sign-up
• Full touch, mouse and keyboard support
• Saved best score and local leaderboard
• Authentic 1980s arcade feel with CRT scanlines and pixel glow

Ready?

Free. Instant. No download.

▶ Play Citadel Defense 21