Gameplay

Metroid provided one of the first highly nonlinear game experiences on a home console. The basic gameplay is a mix of action adventure and platform shooter. The player controls Samus Aran across sprite-rendered two dimensional landscapes, starting with only a weak blaster shot and jumping ability, preventing progress to certain areas of the game world. As the player explores more of the area, they will encounter power-ups that can be used to pass the previously encountered obstacles, allowing them to explore further, as well as backtrack, in order to find more power-ups and advance. While players are tempted to complete the game quickly, as there are multiple endings determined by length of completion time, the concept of gradually increasing abilities and therefore aquiring access to previously inaccessible areas, encourages the player to go back and obtain all available items and power-ups. This style of game play has been a hallmark of the Metroid series from the beginning, but has influenced other series, most notably the post-Symphony of the Night titles of Castlevania. In addition to common enemies that inhabit the world, Samus will encounter bosses that she will need to defeat before progressing further. Defeating an ordinary enemy usually yields additional energy or ammunition; a defeated boss usually unlocks new weapons and/or abilities.

Development

Metroid, and its sister game Kid Icarus, were both developed by Gunpei Yokoi and his team and originally released on the Famicom Disk System. Both titles featured saves slots, unlike the North American release which used passwords to save players' progress. Although Kid Icarus is a more linear title in the majority of its 13 stages, overall both titles feature remarkably similar gameplay as they utilize the same game engine. They were released on the same day in America, and a big selling point for both titles was its use of passwords. Although titled "Sacred Words" in Kid Icarus, the password system is identical in both games. Kid Icarus even features Metroids as enemies in Level 3, the Skyworld, although they do not behave the same as they do in Metroid.

Metroid is notable for being the first video game to feature a female protagonist at a time when the vast majority of games relegated female characters to variations of the "damsel in distress" role. However, this fact was not revealed until the end of the game, and then only if the game was completed within a certain total amount of time. The English instruction manual simply described Samus as a "space hunter" (now "bounty hunter" in Metroid canon) and specifically stated that Samus's identity was "shrouded in mystery." At some points, the English manual used masculine pronouns in relation to Samus, either in error or as deliberate misdirection. Japanese does not use pronouns most of the time if the referent could be inferred, making the surprise easier to carry off in the Japanese version (and the potential for either deliberate or accidental errors less likely). Further, the on-screen character was rendered more or less androgynous, so the game gave no clues to its protagonist's identity until the ending credits.