Need to keep the ship sharp so we can see the details and not clip it with the edge of the picture. Since the picture is big, everything gets stretched out and it does not look so good. Looks good in the thumbnail but the regular size is not so good.
If you can, check out movies/pictures of ships taking off. Almost have the effect but it needs more work. If Doga supports smoke or flame effects, you would be better off using the stuff from the app and postworking it instead of doing it from scratch. If the app does not support smoke effects, maybe you could experiment with semitransparent cones with a non reflective texture and a smoke texture map.