How to Play DefOrbit — Free Browser Space Shooter, No Download

What is DefOrbit?

DefOrbit: Earth Defender is a free browser space shooter where you pilot a ship around Earth and intercept alien invaders. Move your mouse to aim; your ship fires automatically. No download or account is required to start playing.

Choose Classic survival, a five-sector Campaign, or 2-player online co-op. Campaign adds an arsenal of six weapons with four evolution tiers, permanent upgrades, and boss checkpoints.

Game Modes

Classic: Survive waves with the Pulse Cannon on Easy, Normal, Hard, or Endless. Classic has no Campaign loadout, weapon drops, or Q weapon switching.

Classic and co-op keep the original enemies and add new threats as you advance: independent Micro Swarms from wave 6, Spiral Cores and dodging Phantoms from wave 11, and aggressive Rippers from wave 21. Destroying a Ripper with shots releases four fragments that scatter backward before attacking on their own. Bosses still arrive every five waves. Results use the existing Classic and co-op highscore lists.

Campaign Expedition: Complete five sectors with five encounters each, ending in a boss checkpoint. Choose Easy, Normal, or Hard, prepare your loadout, and pick safe or risky routes to earn credits and unlock equipment.

Campaign Endless: Completing Sector 5 unlocks a separate survival mode on the Campaign map. It uses your unlocked Campaign equipment and has its own leaderboard.

Co-op: Two players defend Earth using Classic rules. The host chooses Easy, Normal, Hard, or Endless; Campaign equipment and progression do not apply.

Controls

DefOrbit auto-fires — there is no fire button. Steer around Earth, drop bombs, and switch weapons when you have a secondary weapon in Campaign.

On mobile, move your finger to aim — firing is automatic. Touch buttons handle bombs and Campaign weapon switching. Menus work in portrait, but gameplay requires landscape; rotate your device before launching.

Scoring and Combos

Every enemy kill earns points. Chaining kills quickly builds a combo multiplier shown in the top-left of the HUD. The multiplier increases as you keep up a rapid kill pace — let the combo bar drain and it resets to ×1. Boss kills award large point bonuses, with harder bosses giving more.

Protect Earth's shield to keep your run alive. Classic, co-op, Campaign Expedition, and Campaign Endless results have separate leaderboard views; Guest Campaign runs do not submit online scores.

Difficulty Modes

Classic and co-op offer all four settings below. Campaign Expedition uses Easy, Normal, or Hard; Campaign Endless unlocks after the final sector.

Weapons and Upgrades

Campaign starts with Pulse Cannon, Scatter Shot, and Plasma Lance unlocked. Clear Sector 1 to unlock Homing Darts, Sector 3 for Plasma Burst, and Sector 5 for Ricochet Bolts. Classic and co-op use the Pulse Cannon.

Campaign weapons evolve through four tiers (I → II → III → MAX) through upgrade cards and eligible matching weapon drops. Weapon drops appear only in Campaign solo. The optional Dual Weapon Slot lets you prepare a second weapon before launch; you can also acquire a secondary weapon during a run. Press Q to switch when both slots are occupied. See the Weapons guide for stats.

Boss Encounters

The five boss types are The Phantom, The Serpent, The Crystalline, The Guardian, and The Swarm Mother. Each has a distinct mechanic: teleportation, a segmented body, splitting on death, a rotating shield, or minion spawning. Bosses enter a more aggressive second phase at half health. In Campaign Expedition, each sector ends with one boss and its checkpoint reward. See the Boss guide for strategies and Campaign unlocks.

Co-op Mode

Select CO-OP MODE from the main menu and choose Host. Pick Easy, Normal, Hard, or Endless, then share your room code or invite link. Your friend enters the code or follows the link, and both pilots defend Earth in real time. Co-op always uses Classic rules, independently of the Campaign menu selection.

Campaign Progress and Credits

Guest progress: Campaign saves stay in this browser on this device. Clearing browser storage can erase them. Guest Campaign runs do not enter the Campaign leaderboards.

Cloud progress: Sign in with Google for a separate account save and Campaign leaderboard participation. Guest and account progress are kept separately; signing in does not transfer or merge your Guest progress.

Earn credits by playing Campaign and spend them on equipment, support upgrades, and cosmetics. Campaign skins cost 30 credits each. Credits cannot be bought with real money, and no subscription is required.

Frequently Asked Questions