Thank you for playing the game and for your feedback!
I developed this game using Three.js, a JavaScript 3D library. I appreciate your input about the zombie movement speed. Based on feedback, I recently increased the zombies' walking speed to make the game more challenging.
If the zombies still appear slow on your laptop, it might be due to performance limitations. I'll look into optimizing the game further for lower-end hardware. Thank you for bringing this to my attention!