Hi there! Thank you for kind words.
The flame is just a particle effect produced with LÖVE (love2d.org) framework. The graphics used by the particle is actually already there in the tileset. It only uses one, 16x16 tile from the tileset. In v1 it's {x:160,y:304} in v2 I moved it to {x:208,y:256}.
Anyway, I'm sure it's as easy to setup with any particle system your engine of choice is using :)
Moreover if one would try to use the a frame-based animation for this effect the results wouldn't look as good so there is no point of producing one, hence I'm going to produce one.
I had this questions a couple of times already. I've create an example .love file so you can take a look inside.