One gentle suggestion I would make for future products is to ask artists to cut back on the single Martian close-up--either just head or head and torso. The number of those sketches makes things a little less interesting IMO. I find myself being more interested in the "scene" cards, even when the art may not be as good.
And a sketch like this that capture a moment of tension is really great:
2013 Topps Mars Attacks Invasion Artist Sketch 1 1 Ben Dunn 2 Card Puzzle | eBay