I think all Dragon Slayer games are entirely in English? It is definitely playable. Nice intro music too. I think the game has a custom namco sound chip also used in such games as Rolling Thunder. If you like sidescrolling platforming games where you level up and pick up items, I think this is a nice game.
Played on twin famicom console.
Japanspel currently has 5,696 views spread across 1 video for Dragon Slayer. His channel published less than an hour of Dragon Slayer content, making up less than 0.07% of the total overall content on Japanspel's YouTube channel.