Godot 4 GPUParticles2D not showing? 5 reasons your particles aren't appearing

In Godot 4, GPUParticles2D can fail to appear with no warning, so setup checks are essential.

Common causes include a missing ParticleProcessMaterial, emitting set to false, an incorrect visibility_rect, or amount/lifetime values that are too low.

These silent configuration issues can make the node exist while the effect looks broken, wasting debugging time.