Game over process:

1. Player gets hit by asteroid, or hits the ground too fast
2. Gameplay “freezes” and does not allow player input
3. Rocket explodes
4. Score appears, alongside button to retry
5. When player presses retry button → restart scene

What happens during gameplay “freeze”?

• Player input disabled
  • freezing rigidbody Y also works for this, but should also permanently hide thruster fire object
• Stop asteroid spawner from spawning anything
• Stop rocket from moving (freeze rigid body Y?)
• If collided with asteroid, stop asteroid from moving
• Stop year count

After rocket explodes:

• Hide rocket (reduce local scale to 0)
• Destroy asteroid, if collided with asteroid