Castlevania: The Adventure, known as Dracula Densetsu (ドラキュラ伝説, officially translated The Legend of Dracula) in Japan, is a platform game released for the Game Boy in 1989. It is the first Castlevania title for the system. Castlevania: The Adventure was re-released as part of the Konami GB Collection compilations in Japan and Europe. A remake titled Castlevania: The Adventure ReBirth was released as a WiiWare game for the Wii.
Set a century before the events of the original Castlevania, the player controls an ancestor of Simon Belmont named Christopher Belmont who goes on a quest to defeat Dracula.
The game consists of four stages, and unlike other Castlevania games, there are no sub-weapons, but hearts are used to restore health. The player has three lives, after which the game ends. Weapons can be upgraded, such as the whip into the chain whip and flame whip, but any enemy damage will downgrade an upgraded weapon. There are no stairs, unlike other Castlevania games. At the end of each level, there is a "primary evil" to confront. Players can utilize crystals, hearts, and crosses of gold. There is also a point counter, and at 10,000 points, a player receives an extra life, and also receives one for every 20,000 points after that. Each stage also has a time limit in which to complete the level.
Source: Wikipedia, "Castlevania: The Adventure," available under the CC-BY-SA License.