D3 has announced that it will be releasing Earth Defense Force 4.1 for Steam on July 18th, with a regular price of $49.99. However during launch there will be a 30% discount. The game will feature full audio in both English and Japanese, as well as achievments and online co-op. Earth Defense Force 4.1 features 80 missions in which players face off against giant alien insects, with over 800 weapons to use against them.
Earth Defense Force 4.1 is already available on PS4.
Source: Press Release