Astle of Dragon, known as Dragon Unit (ドラゴンユニット?) in Japan, is a side-scrolling action video game created for the arcade by Athena in 1989 and later converted for the NES in 1990 with gameplay and graphics suitably adapted to the limitations. from the game console.

The plot varies slightly between the arcade version and the NES version, the latter being somewhat more elaborate and with the names of the characters changed.

In the arcade it is simply told that a dragon named Zuriv captured the princess of the kingdom of Wenlary and two young kings named Duke and Narda set out to rescue her from her.1

For his part in the plot of the NES version, the chief of the dragons, Darklarza, had been terrorizing the kingdom of Offeria for two decades, forcing King Boros into exile with his bravest knight, Geraden, who protected his kingdom. castle.

Darklarza launched an attack on the king's fortress which turned out to be a diversionary move whereby his scion managed to kidnap princess Amoreena and mortally wound the king while Geraden was trying to finish off the enemy leading the attack.

Thus, Geraden was forced to fight on a journey to Darklarza's castle to defeat him and rescue the princess.