Space Invaders Tutorials
Wave-by-wave strategy, diagonal shooting techniques, and tips to survive the fastest alien hordes.
What is Space Invaders?
A classic arcade shooter where a grid of aliens descends from the top of the screen. Shoot all aliens before the grid reaches your ship. Each cleared wave starts a new, faster wave. The goal is to survive as many waves as possible and maximise your score.
Step-by-step: Your first wave
- Press Space or tap the screen to start the first wave
- Move the ship left or right to position for a clear shot
- Press Space or tap to fire at the alien grid
- Clear all aliens to complete the wave and earn a wave bonus
- Each new wave is faster — survive as long as possible
How diagonal shots work
When you fire, the bullet inherits your ship's horizontal velocity at the moment you press fire. If you are moving right and fire, the bullet travels diagonally right. Use this to reach aliens in corners without repositioning the ship directly beneath them.
Wave design explained
| Wave | Grid size | Alien speed | Bullet cooldown | Wave bonus |
|---|---|---|---|---|
| 1 | 4×3 | Slow | 800ms | 150 |
| 2 | 4×4 | Medium | 700ms | 300 |
| 3 | 5×4 | Fast | 600ms | 450 |
| 4+ | 5×4+ | Increasing | Decreasing | +150 per wave |
Scoring formula
Each alien kill scores level × 10 points. Clearing an entire wave earns a wave bonus of 150 × level. Prioritising full wave clears over individual kills is far more score-efficient — the wave bonus at Level 5 is 750 points, equivalent to 75 individual kills.
When to fire vs when to reposition
Each shot has a cooldown. Do not waste shots on aliens that are not in your current firing line. Instead, reposition the ship to align with a cluster of aliens, fire a burst, then move again. Firing while stationary and waiting for the cooldown is often safer than firing while moving.
Controls reference
| Action | Desktop | Mobile |
|---|---|---|
| Move ship | Arrow keys / A / D | Drag left or right on canvas |
| Fire | Space | Tap canvas |
| Restart | R key | Restart button |
Top 5 tips to survive longer
- Clear the edges of the alien grid first — corner aliens are hardest to reach as the grid shrinks and speeds up.
- Use diagonal shots to reach corner aliens without moving all the way across the screen.
- Stay mobile — a stationary ship is an easy target for alien bullets.
- Do not panic-fire; wait for the cooldown to expire and aim deliberately.
- Watch the descent speed, not just the alien count — the grid descends faster in later waves even if fewer aliens remain.