The developers of this game are sadists who should be consigned to play it for the rest of their feeble careers. The "hidden objects" are microscopic and less hidden than camouflaged and buried.
For example Gettysburg 1862 I was asked to locate a Canadian Flag. Having pored over the picture to no avail I used one of the miserly 3 "help" units allocated to a game where you need to find 100+ objects and help didn't identify the location of the flag! I don't believe that there actually is one.
Summary - deeply disappointing sadistic, torturous wasste of time and money. Take up tiddlywinks instead.