ボキャブラリーモンスターワールド is an educational RPG game for iPhone that helps players learn English words while playing. The game features a wide variety of monster characters that are actually English words. Players can collect these monsters and progress through the game's learning quests.

With a unique and original storyline, the game offers an immersive world where players can explore and learn. The fate of the world is at stake, and it's up to the players to save it by mastering English vocabulary.

In addition to the main quests, the game also includes mini-games that provide opportunities for players to review and reinforce their English vocabulary.

Please note that the game is recommended for iOS 10.0 or later and iPhone 6s or later. However, there may be instances where the app does not function properly even on recommended devices.

Monthly subscription is available for $4, which grants access to chapters 4 and beyond in the game's story.