Valkyrie no Bouken - Toki no Kagi Densetsu

Valkyrie no Bouken - Toki no Kagi Densetsu is a side-scrolling action-adventure game developed by Namco for the Nintendo Entertainment System (NES) in 1986. The game follows Valkyrie, a female warrior, on her quest to find the key to the door of time and save the world from evil forces. The game features platforming elements, RPG-like mechanics, and a unique weapon system that allows players to switch between different weapons during gameplay. It also has a two-player simultaneous mode where players can control Valkyrie's companions.