InvaderZ
Play InvaderZ free on RetroPlayNow: a Space Invaders shooter where every wave evolves with a genetic algorithm. Aliens inherit speed, fire rate and movement from the survivors — last as many generations as you can.
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How it works
Play, earn points and Retro Coins: the shared currency across every RetroPlayNow game. Unlock badges and climb the leaderboard! Your progress is saved automatically on this device.
InvaderZ takes the most iconic arcade shooter of all time and gives it a twist worthy of the machine age: every wave of pixel invaders is the product of a genetic algorithm. Each alien carries a genome — its lateral speed, how fast it descends, how often it fires and how it wobbles — and the aliens that survive your shots longest pass those genes on to the next generation.
The game keeps the classic vertical shooter format: move your cannon along the bottom of the screen, fire up at the descending formation, and dodge the incoming alien fire. Your lasers fire as fast as you can tap, and every invader you destroy adds 10 points to your score.
What makes InvaderZ unique is evolution. When you clear a generation, the survivors' genomes are selected by survival fitness, crossed over in pairs and mutated. The next wave is measurably different: faster formations, quicker descent, more aggressive firing and new wobble patterns. No two runs feel the same, and the aliens literally learn from their fallen predecessors.
You have 3 lives, and when the last one is lost your score is submitted to the RetroPlayNow leaderboard. The platform converts 100 points into 1 Retro Coin, so the players who outlast the most generations walk away with the biggest coin stacks.
How to play InvaderZ
- Move the cannon. Use the left and right arrow keys (or A/D) to slide your cannon along the bottom of the screen. On mobile, drag your finger to move.
- Shoot the invaders. Press Space (or tap on mobile) to fire upward at the descending formation. Every invader destroyed adds 10 points.
- Dodge enemy fire. Invaders fire at rates set by their genes. Read the descent patterns and keep moving to avoid the laser rain — you have 3 lives.
- Clear a generation to trigger evolution. Destroy the whole wave to earn a 50-point bonus and spawn the next generation, bred from the aliens that survived you the longest.
- Earn Retro Coins. When the last life is lost, your score is submitted automatically and converts to Retro Coins at 100 points per coin.
Frequently asked questions
What is InvaderZ?
InvaderZ is a Space Invaders-style shooter where the invaders evolve with a genetic algorithm: each wave is a new generation with genomes for speed, descend rate, fire rate and movement wobble.
How do the invaders evolve?
When you clear a wave, the genomes of the invaders that survived longest are selected by fitness, crossed over in pairs and mutated. Later generations are faster, descend quicker and fire more aggressively.
What are the controls for InvaderZ?
Use the left and right arrow keys (or A/D) to move your cannon and Space to fire. On mobile you can drag to move and the cannon fires automatically.
How do I score points in InvaderZ?
Every invader destroyed is worth 10 points and clearing a full generation pays a 50-point bonus. Surviving more generations means more invaders destroyed and a higher score.
How do I earn Retro Coins in InvaderZ?
Your final score is submitted automatically when you lose your last life, and the platform converts 100 points into 1 Retro Coin.
