No worries at all! I actually just used a 16x16 opaque black circle with a particle emitter in Construct 2. It took some fine-tuning to get it to look right though.
I could give more details about specifics if you like, but I'm not sure if it'd be helpful outside of Construct!
No worries, I'm glad if it helped a bit. Yeah, Godot is the engine I'm focusing on learning at the moment - I just hopped back onto Construct 2 to put this quick demo project together. :) Best of luck with the smoke effect in Godot!
