I'm sorry but i'm at too low level for coding stuff like yours :)
I try to explain it in words.
Actually your flame have the particles that go only up,if you make them go left and right (to simulate a sort of wind,like if you lit a torch and put it near a source of wind and then you move the torch).
I think that a repetitive movement from left to right and so on would be perfect.
Did you try to use only the pixel command(to draw the pixel)with the rnd function at a lower seed and make each particle with different "life"?(how long a particle stay visible...)
I try to explain it in words.
Actually your flame have the particles that go only up,if you make them go left and right (to simulate a sort of wind,like if you lit a torch and put it near a source of wind and then you move the torch).
I think that a repetitive movement from left to right and so on would be perfect.
Did you try to use only the pixel command(to draw the pixel)with the rnd function at a lower seed and make each particle with different "life"?(how long a particle stay visible...)