The developers had plans to release Steel Empire on PC which the PC release ACTUALLY happened last year in Japan via physical copy that can be obtained in retail stores. Most of modern PC game releases are probably on Steam but that's not the only PC release out there. You may be surprised to find physical copies of those PC games in the retail gaming stores and you may expect like a few DVD-ROM discs or something. Other PC games also have the GOG releases along with other Steam alternatives but then, the Steam service is already a better choice for digital purchases of PC games there.
Steel Empire is originally released on Megadrive/Genesis before getting remade on Game Boy Advanced and 3DS. It's a shooter game where you can shoot down enemies in left or right direction and you don't lose your ship in one hit. The game gives you multiple lives and the Vital Bar at its start and has various powerup items and other items for you to collect, including the item that gives you an extra life/ship.
The Steam version of Steel Empire is expected to come out in September this year in which people outside of Japan are able to enjoy it if they're interested. The PC version is based on 3DS version with HD interface and pixellated graphics which I find it as a strange move to me. It's not the only 3DS game to be ported to other game platforms but then, there shouldn't be any sign of pixellation whatsoever.
One development problem from the developers, the source code for the Megadrive and cancelled arcade versions was lost so it posed them a challenge when remaking the game for the Game Boy Advance.
