9 Pioneering Video Games EVERYONE Forgets
5. Courageous Perseus
Although it came out around the same time as the commonly commended Dragon Slayer and Hydlide, the 1984 action-RPG Courageous Perseus easily outdid them in terms of ambition, scope, and complexity.
Building upon modest predecessors Panorama Toh and The Tower of Druaga, its advanced mixture of hack-and-slash combat and more traditional RPG elements breathed new life into the subgenre. Without it, we wouldn’t have Alundra, the Ys adventures, Times of Lore, or a little-known gem called The Legend of Zelda.
On that note, and as specified by Giant Bomb, Courageous Perseus was the "first fully-scaled on-foot open-world game," with its outdoor freedoms going beyond the then-standard practice of dungeon-only exploration.
It took place on an island, too, and allowed players to go to other isles via raft transport.
As such, it arrived well ahead of Final Fantasy X, The Legend of Zelda: The Wind Waker, Chrono Cross, Rune Factory: Tides of Destiny, and Suikoden IV (in addition to countless other proteges with similar settings).