We will soon be updating Battle Marine to distribute the ROM file of the GBA version of Battle Marine as a bonus for purchasing the game on Steam.
The GBA port is coming along very nicely and is ready for release once the ending and balance adjustments are completed.
We will probably be able to update the game by the end of June 2025.
The distribution method will be the same as the GBA version of Battle AirForce and will be made available without additional charges.
https://store.steampowered.com/news/app/3476490/view/547857372725379988