I'm interested to know how you did that organic weird moving background, is it a 2D shader? The effect is really cool!

Yeah it's a 2D shader. :)

It's base is a seamless noise texture. The colour of the noise is sampled by a gradient texture, but the sampling coordinates is offset with time to make it look alive. I'll share the shader code later.

Edit:

shader_type canvas_item;
uniform sampler2D noise;
uniform sampler2D color_ramp;
uniform vec2 offset;
varying vec2 UV2;
void vertex() {
 UV2 = VERTEX / 800.0;
}
void fragment() {
 float color_off = sin(TIME + FRAGCOORD.x / 50.0);
 COLOR = texture(color_ramp, texture(noise, UV2 + offset).rr - color_off*0.015);
 
 COLOR.rgb *= mix(1.0 - length(UV - 0.5) * 2.0, 1.0, 0.7);
}

Oh, ok I "think" I understand :) Thanks!