Invasion of Japan

Joni Nuutinen

About this game

Allied Invasion of Japan 1945 is a turn based strategy game set on the Pacific theater modelling the planned but not carried out WWII operation. From Joni Nuutinen: by a wargamer for the wargamers since 2011. Latest patches out on August 2026.

This scenario covers Operation Olympic (Allied landing on Kyushu), which was the first part of Operation Downfall (the invasion of Japan). The second part, Operation Coronet, was supposed to take place in 1946.

By default, the campaign includes Allied naval fleets (battleships, aircraft carriers, dive bombers, tankers) to fight Japanese submarines and kamikazes. The entire naval element can be turned OFF from the settings. The allied plan called for landing on three separate zones, and the supply flow is partly calculated based on this, but nothing prevents the player from gaining control of the seas and carrying out a landing elsewhere on the island to speed up the conquest.

In this campaign, you are in command of the US amphibious force tasked with seizing Kyushu, the southernmost of the Japanese home islands, to set the stage for the second stage of Operation Downfall.

The geography of Japan has forced the Allies to choose a predictable strategy, and the Japanese have set up their forces well to take on the American onslaught. To defend Kyushu, Japan is planning to throw in most of its troops, as well as a huge number of local fighting units and what's left of its naval might. The fact that Japan is starting to run low on supplies is counterbalanced by the incredible supply distances that allies have to deal with, not forgetting kamikaze planes and midget submarines.

FEATURES:

+ Thanks to a huge amount of in-built variation and the game's unique AI, each game provides a different war gaming experience.

+ Settings: A ton of options are available to alter the feel of the gaming experience: Change difficulty level, hexagon size, Animation speed, choose icon set for units (NATO or REAL) and cities (Round, Shield, Square, block of houses), decide what is drawn on the map, weather and storms, and much much more.


"The Japanese soldier was a fine fighting man. He was well-trained, well-equipped, and very good at fighting in jungles and mountains. He was also disciplined and fanatical, and he would fight to the end. The Japanese army was also very well organized and led. It had a clear understanding of its objectives and it was always prepared to adapt its tactics to meet the changing situation."
-- General William Slim in his book Defeat into Victory

Ratings and reviews

Decent hypothetical battle game of a potential invasion of Japan. The only issue with this game is that every 3-4 turns, instead of the rapid end of turn to the next turn, the game has a 10-12 second hesitation before going to the next turn. Otherwise a challenging game

Excellent game. My first of Joni's, but this convinced me I need to eventually buy them all. Really superb experience!

This is a regiment-level stimulation of Operation Olympic, the battle that never happened, and it's got all the features you love in this series and more, such as engineer units and aircraft carriers. Logistics plays a part as always, with supplies for the ground troops and fuel for the naval units needing to be brought in. I definitely like having the engineers clear terrain and build roads; it makes shuttling units between the front line and hospital so much quicker.

What’s new

+ Supply order change: Route to airdropped supply will be checked first for Generals and artillery units (that do not consume supply), to prevent combat units consuming all airdrop supplies before route-only checks are done