The first volume was good; the second volume is even better. In general, the 'war years' covers July 1916 to October 1917 and sees Indy go from footslogger in the trenches to a captain in military intelligence. From the outset it is very important to keep in mind that the original intention of Indiana Jones was to recreate a story/comic book hero; the 'silly' sounding chapter titles have all been devised with that in mind, and with that in mind I feel many criticisms are unwarranted.
Rather than critique all eight 'movies', I shall focus on what I think is the best one: 'Oganga'. What appeals about this episode (East and Central Africa December 1916/January 1917) is that it covers a lot of ground. It commences with trench warfare, (and like the 'Trenches of Hell' - first episode) with a limited budget does a fair job of showing the horrors of the war. What both these episodes share is the idea of creating a human background: yes, there is a high body count (Indiana himself polishes off quite a few), but there are a number of supporting actors that do only support but whose partial verbal characterized presence helps to create a more natural feel; there are some very nice touches and great attention to detail rather than the usual awkward unrealistic silent treatment of the supporting cast. This is something that is missing from so many so-called Hollywood blockbusters, but here, with a budget of $1.5 million. Disobedience of orders leads to a successful engagement, and Indiana is suitably smug (again, one of the strengths of the series is that he does have feet of clay and is capricious and weak as the next man; he displays the rashness of youth, conceit of rank). The second part involves a hazardous mission from one side of Africa to the other, in which Albert Schweitzer pops up, with some nicely scored Bach to boot. The perilous river journey has shades of Conrad but as nods rather than outright imitation.
Overall, the second volume is great - the extras are much better than those of the first volume. The only slight irritation is the bucking of the original chronology; Austria March 1917 is paired with Petrograd July 1917 while Barcelona May 1917 is set with Prague August 1917. This has been done I think to keep a `serious' pair together while the latter pair is comic in tone: the weighty end of Petrograd would have been ruined with the farcical Prague following it.
I can't wait to start on with volume three now, but have the feeling that volume two will remain the best one by far.