Horizontal health meter? Get outta here

This portion of the document details what information ought to be communicated to the player via the HUD. This includes the player’s energy, as well as how the game will horizontally scroll. You can see the HUD has a score field, and indeed, this first Mega Man was the one and only game in the series to include that arcade-like element. But the health meter is horizontal, in contrast to the vertical layout used by the final game and most of its sequels.