What is Neural Slime Volleyball?
Neural Slime Volleyball is a browser remake of the old Slime Volleyball game, where two half-circle blobs bounce a ball over a net. Your opponent is controlled by a small recurrent neural network that learned the game on its own.
David Ha, known online as hardmaru, built it in JavaScript in 2015. He trained the AI with neuroevolution: a population of agents played each other, the top 20% survived and were mutated, and after a few hundred generations he had a player he described as 'virtually impossible to beat by a human player consistently'. It reached the Hacker News front page in May 2015, and the game later became Slime Volleyball Gym, a test environment used in reinforcement learning research.
What You Can Do
- Play volleyball against a self-taught neural network
- Control your slime with the arrow keys or the mouse
- Play on phones and tablets with touch controls
- Try the easier version if the main AI is too strong
- Watch how an AI with no hand-written rules moves and plays
How to Play Neural Slime Volleyball
- Open otoro.net/slimevolley in your browser.
- Move left and right with the arrow keys and press up to jump.
- Hit the ball over the net and keep it off your side.
- Switch to the easy version if you keep losing.
Is Neural Slime Volleyball Free?
Neural Slime Volleyball is free to play in your browser with no account, ads or purchases.
Who Will Enjoy It?
- Retro game fans who remember Slime Volleyball
- Students curious about neural networks and evolution
- Anyone who wants a quick game with a tough opponent
- Machine learning fans who know hardmaru's work
Websites Like Neural Slime Volleyball
- Genetic Cars: Watch evolution at work as random shapes learn to drive.
- Lichess: Another free place to test yourself against a strong computer.
- The Evolution of Trust: A playful look at strategies that win and lose over time.
Frequently Asked Questions
Is Neural Slime Volleyball free?
Yes. It is free in your browser with no sign-up.
How was the AI in Neural Slime Volleyball trained?
With neuroevolution: agents played each other and the best were kept and mutated over hundreds of generations.
Can I play Neural Slime Volleyball on my phone?
Yes. It supports touch controls on phones and tablets.