Space Invaders

How to play Space Invaders

Defend Earth across 50 hand-tuned levels of escalating alien waves. Move your ship, fire bullets, dodge enemy shots, and pick up power-ups that drop from killed aliens. Every tenth level ends with a boss battle. Clear all 50 to unlock harder difficulties and the endless survival mode.

Controls

• Keyboard: Arrow keys or A / D to move, Space to fire, P to pause, M to mute.
• Mouse: the ship follows your cursor horizontally; click or hold to fire.
• Touch: drag anywhere in the play area to move; tap to fire. An auto-fire toggle is available in the pause menu for casual play.

Game modes

• Arcade — the classic one-life-bar challenge. Play through 50 levels in a single run; if your lives run out, the run ends and only your final score is recorded. No mid-run save. This is where the global high score is set.
• Casual — automatic checkpoint after every cleared level. Close the tab and come back where you left off. Best for longer sessions broken up over time. Casual scores are tracked separately so they don’t dilute the arcade leaderboard.
• Endless — unlocked after clearing level 50 on any difficulty. Aliens keep escalating forever; survive as long as you can.

Difficulty

• Normal — standard tuning. Recommended for a first playthrough.
• Hard — unlocked after first clear. Aliens have more HP, fire faster, move quicker. Scores multiplied by 1.5.
• Insane — unlocked after a Hard clear. The numbers get rough. Scores multiplied by 2.5.

Enemies

• Grunt — the standard alien. Slow, fragile, fires occasionally.
• Striker — fast, fragile, fires in bursts.
• Tank — slow but takes three hits to kill. Drops better loot.
• Kamikaze — dives at your ship instead of firing.
• Splitter — breaks into two smaller aliens on death.
• Sniper — stays at the back and fires aimed shots straight at you.

Power-ups

• Rapid Fire — 2× fire rate for 10 seconds.
• Triple Shot — three-way spread for 10 seconds.
• Shield — absorbs one hit.
• Extra Life — rare. Adds one to your reserve.
• Slow-Mo — enemies slow down for 5 seconds.
• Nuke — clears all on-screen bullets and weak enemies. Very rare.

Bosses

At levels 10, 20, 30, 40 and 50 you face a boss with a health bar and two or three attack phases. Bosses telegraph their attacks — learn the pattern, find the gap, and chip down the bar.

Scoring

• Each enemy type has a base score (Grunt 100, Tank 500, etc.).
• Combo multiplier: rapid consecutive kills build a multiplier up to 5×. The combo drops if you don’t kill anything for ~2.5 seconds.
• End-of-level bonuses for remaining lives, accuracy, and clear time.
• Boss kills award a large flat bonus that scales with sector.
• Hard and Insane difficulty multiply every point earned.

Strategy tips

• Prioritise threats. Snipers and kamikazes will kill you faster than grunts. Pick them off first.
• Don’t hoard Nukes. Use them to break combos out of trouble or wipe a wave when your shield is gone.
• Triple Shot turns boss fights short. Save it for boss waves when you can.
• Combo is the real high-score lever. A messy 50-kill run scores worse than a tight 50-kill chain at 5×.

Offline play

Once the page is loaded, the whole game runs in your browser — no servers, no internet needed. Your best score and casual progress are stored on your device and uploaded to the leaderboard the next time you reconnect (only if you’re logged in — guests play for fun and their scores stay local).