For being tools of war, the Advance Wars units look quite cute, thanks to their "super-deformed" proportions and bright colours.
Although the map sprites all look the same (except for the colours of course), the sprites from the battle animations are different for the units from each army, although sometimes they do look a lot alike. The Subs for instance all have pretty much the same basic hull, only the rudder and the command tower are different.
And if you look closely, you can see that difference even in the small versions too! Like I said before, it's that sort of thing that I really like to capture in the paper versions. ;o)
As you can see, the Blue Moon Sub is almost finished too, stay tuned!