This movie excellently brings such combat to life, and (unlike LAST VALLEY which was a small slice of life) covers the full breadth of the conflict... culminating in the huge and decisive battle in the Tsushima Straights between the fledgling Japanese force and the mighty 40-ship Russian Baltic Fleet which had sailed around the world for 6 months to fight them.
This film was the final penultimate film for Japanese special effects director Eiji Tsuburaya, who provides some of his best, most detailed, and most convincing miniature work ever. There's a healthy number of composite shots to blend the miniatures with the live action, and the effects are overall quite amazing (though not completely convincing). The acting (especially with American expatriates as Russians) leaves some to be desired, but one has to give the Japanese credit for improvising since Russia angrily refused to cooperate with this production at all.
The land battles during the siege of Port Arthur are quite large and exciting, even genuinely moving in a few places as you can really feel General Nogi's frustration with the extremely high casualties and lack of progress. Mifune brings a great gravitas to his role as Togo, dubbed "Japan's Nelson" at the time, and several of the better character actors from the early Godzilla movies pop up as random officers. The ending features a similar speech to Christopher Plummer's in the following year's WATERLOO, which gives all the fun, excitement, and jingoism a more somber spin.
I must also mention the excellent cinematography, staging, and music which give the film a very polished look of a monumental, groundbreaking epic. More so than most other war films of the time. Sure this film takes a few Historical liberties (mostly to simplify the more complex battles) but it still provides a lot of eye-opening insight on a largely forgotten, but significant war (in that it set the stage for the Russian Revolution AND the second Sino-Japanese war).
All in all, I was not disappointed. For a Japanese war movie, it's the best I've seen, right up there with the sadly rare STORM OVER THE PACIFIC.