由 Atlus 開發，並由 Hudson Soft 於 1988 年在任天堂 Famicom（紅白機）上推出，日本版名為《亀の恩返し ウラシマ伝説》，北美版則稱為 Xexyz。遊戲大膽將日本古典民間故事「浦島太郎」與賽博龐克風格的科幻元素結合，創造出極具特色的世界觀，成為紅白機時期的隱藏經典之作。

被譽為當時 Famicom 中完成度極高的「混合型動作遊戲」，融合了探索、角色互動與高速射擊元素。遊戲的視覺設計從傳統和風的場景開始，隨著劇情發展逐漸轉向機械化的未來都市，甚至延伸至太空。這種從民間故事到科幻世界的反差，是本作最大的魅力之一。音樂同樣出色，旋律節奏感強烈，特別是在 Boss 戰與射擊關卡中，充分展現 Atlus 對音效的用心。

故事設定在地球未來約兩千年後。浦島太郎救了一隻烏龜後前往龍宮城，度過愉快的時光，返回地面卻發現世界已被外星軍團「Giga-Za-Game」統治。受改造版乙姬的委託，太郎穿上動力裝甲，踏上拯救星球和平的戰鬥旅程。這種結合民間傳說、時間跳躍與科幻戰鬥的設定，使劇情既奇幻又令人印象深刻。

操作分為兩種主要模式：橫向卷軸動作探索與水平射擊。探索模式中，需要在城鎮收集情報、購買武器，核心玩法在於「武器搭配與升級」。太郎初始只能發射弱小彈，但可以透過升級獲得球型、雷射或火焰噴射等多樣化武器。射擊模式則在關卡末端展開，太郎駕駛烏龜或機械造型載具進行高速射擊，操作流暢並搭配華麗特效，擊敗巨大 Boss 帶來極高爽快感。跳躍操作精準，地圖中隱藏房間與捷徑也讓探索充滿趣味。

推出時雖未引起大規模話題，但後來逐漸獲得「邪典經典」的地位。評論家讚賞其荒誕卻完整的世界觀，浦島太郎手持雷射的奇異設定雖離奇，但遊戲本身平衡性與挑戰性極佳。北美版 Xexyz 以高難度與獨特機械風設計受到復古遊戲玩家追捧，成為收藏佳品。

歷史上，《亀の恩返し / Xexyz》是 Atlus 早期的重要嘗試，展現後續《女神轉生》等系列中「不受單一類型限制、自由創新的設計精神」的雛形。這款遊戲被認為是紅白機時期最具想像力且突破性的一款作品，充分展現了 8 位元動作遊戲的創意極限。

This game, developed by Atlus and released by Hudson Soft in 1988 for the Nintendo Famicom, is an action-shooting RPG known in Japan as Kame no Ongaeshi: Urashima Densetsu and in North America as Xexyz. It is a hidden gem that boldly fuses the classic Japanese folktale of Urashima Taro with a cyberpunk-inspired science fiction setting, creating a uniquely memorable world.

The game’s design is often praised as a remarkable hybrid action experience, blending traditional story-driven exploration with high-paced shooting mechanics. The visual style starts with a traditional Japanese aesthetic, reflecting the folktale origins, but gradually transitions into mechanized futuristic cities and even outer space. This unexpected shift from folktale to sci-fi forms the core of its distinctive charm. The soundtrack is equally engaging, with catchy, fast-paced tracks, particularly during boss battles and shooting stages, showcasing Atlus’ attention to audio detail.

The story unfolds in a far-future version of Earth, roughly 2,000 years after the events of the folktale. Urashima Taro, having rescued a turtle, visits the Dragon Palace and enjoys a time of happiness before returning to the surface, only to find the world dominated by an alien army called the Giga-Za-Game. Tasked by a cybernetic Princess Otohime, Taro dons a powered suit and battles to restore peace to the planet. This blend of folklore, time travel, and sci-fi combat creates a truly remarkable narrative.

Gameplay is divided into two main modes: side-view action and horizontal scrolling shooting. In the action segments, players explore towns, gather information, and purchase weapons, emphasizing strategic weapon use. Initially, Taro’s attacks are weak, but he can upgrade to a variety of weapons, including balls, lasers, and flamethrowers. The shooting segments take place at the end of stages, where Taro pilots turtle- or mech-shaped vehicles in intense shoot-em-up sequences, combining fast-paced controls with visually impressive effects. Jumping mechanics are precise, with hidden rooms and shortcuts rewarding careful exploration.

Upon release, the game did not achieve major commercial attention but later gained a cult following. Critics have praised its bizarre yet coherent world, with Urashima Taro wielding lasers in a cyber-fantasy setting, noting that despite its surreal premise, the game’s balance and challenge remain solid. The North American version, Xexyz, is especially regarded for its difficulty and mechanical design, making it a sought-after item among retro game collectors.

Historically, Kame no Ongaeshi / Xexyz stands out as an early Atlus experiment, hinting at the creative freedom and genre-defying innovation that would later characterize series like Shin Megami Tensei. It is celebrated as a bold, imaginative title that pushed the boundaries of what a Famicom action game could achieve.