I've been thinkin that is it possible to have metallish reflections on sprites etc. So you could have sky reflected into your aircraft or whatever needed. Or you could have chromed guns that would look awesome.
So the challenge is to create a metallish looking texture or sprite that can be used in Construct and that it would reflect some of surroundings on it. This might sound hard but I remember seeing 2d engine which had effect like this and I got feeling that this could be made with FX..
Good Luck Winner gets cookie!