The sixth game in the interconnected Ys series of games, the Ark of Napishtim is the first English release of a Ys game since Ys III. However, that doesn't stop the story from being connected to many older games fairly directly.
The opening cutscene shows Adol, the series' hero, being helped out of a troubling situation with local guards by an unknown person. The person turns out to be an old friend of Adol's from an older game. This is not made clear, however, and new players are pretty much kept in the dark about specifics other than "they know each other". The group escapes on a boat, which crashes, leaving Adol to drift ashore onto an island. He is discovered by the elf-eared, tailed inhabitants of the island, who fear him. With the help of his new acquaintances, he must discover the secret of the island.
Gameplay is really simplistic. Similar to the Legend of Zelda, Olan runs around on a map slashing the little critters that get in his way. He can equip a weapon, a shield, a suit of armor, an accessory, and a tool. Besides the use of tools, the entire game is played with the square button (attack) and, rarely, the X button (jump). Olan can level up after killing enough monsters, which raises his maximum HP. Finally, Olan can cast magic using his sword, if it's upgraded properly. There isn't a lot besides those things that can be done, and the game becomes monotonous fairly quickly.
The PS2 version of the game changes several graphic types from the PC version - namely, the de-Anime-ization of the game. The portraits are still anime-styled, but the animated cutscenes are replaced with CG ones, and the in-game sprites are replaced with similarly shaped 3d models. The cutscenes, at least, can be fixed by using a cheat, so if you'd prefer the better-looking animations to the slapped-on computer generated scenes, feel free to use it. The music and voice acting isn't really notable, good or bad.
As a whole, the game is boring, lacking most of the options and excitement of its contemporaries in the field. The story isn't exciting enough to be worth the boring gameplay, and the gameplay isn't engaging enough to support the drab story.