Versions

Regions

The US and Japanese releases of this game play exactly the same, and both are accepted for runs.

Text on the Japanese cart takes approximately 0:28 seconds longer than the US version. Much of this is locked in stone, such as the passageway before Dark Moon, and the player cannot mash through any text boxes to adjust this.

The megaman leaderboard .net timing will adjust your time for region automatically to compare a US cart time to a Japanese cart time.

Hardware

The original release is a Super Gameboy enabled Game Boy Cart. The only other official releases are the 3DS Virtual Console, and the Switch Game Boy.

Each version is valid for runs, however the 3DS version has longer invincibility frames for enemies. This is apparent from the Jupiter/Electric Shot weapon get demo (as noticed by Brook)

If using Super Game Boy 1, note that your time will be adjusted by the leaderboard to be 102% of the original time due to speed differences. Super Game Boy 2 runs closer to the correct speed.

Game Cube Game Boy Player runs at an appropriate speed.