《天誅4》（Tenchu 4 / てんちゅう4）是由Acquire開發、FromSoftware發行的潛行動作遊戲，於2008年首次在Wii平台上推出。是經典潛行暗殺遊戲《天誅》系列的正統續作，同時也是該系列首度登上Wii平台。繼承系列以忍者暗殺為核心的潛行玩法，同時結合Wii的體感操作，以更直覺的方式體驗暗殺與潛行的快感。

故事背景設定於架空的日本戰國時代，兩位主要忍者角色「力丸」與「彩女」，分別效忠於「織田 松之信」大人，致力於保衛領主與維護和平。從力丸奉命調查一宗神秘失蹤事件開始，逐步揭露涉及叛亂、陰謀與妖術的黑暗計畫。彩女在故事初期因為任務失敗而身受重傷，被敵方俘虜洗腦，甚至與力丸對立。隨著劇情推進，兩人身份與命運彼此交錯，玩家將分別扮演這兩位忍者，逐步揭開幕後勢力與邪惡陰謀，最終阻止國家毀滅的危機。

在操作與系統方面，充分運用Wii遙控器與Nunchuk的體感操作特性。移動與視角控制透過Nunchuk操作搖桿與按鈕，而暗殺與攻擊則利用Wii遙控器進行揮擊與指向。當靠近敵人背後，畫面會出現提示，只需按下按鈕並配合揮動Wii遙控器，即可觸發各種華麗而血腥的暗殺動作，根據接近角度與忍具道具種類，會出現不同的暗殺演出。此外，導入「忍術道具」與「環境暗殺」系統，利用煙霧彈、毒針、陷阱或利用場景中的屋樑、河流、樹叢等環境地形來潛伏、偷襲或藏匿屍體，增加潛行策略性。

另一項特色是「恐懼系統」，透過不斷暗殺與威嚇，敵人的警戒值與恐懼值會逐漸上升，當恐懼達到極限，敵人甚至可能放棄抵抗或逃亡，讓潛行過程更加充滿心理壓力與控制感。此外，還提供不同的任務目標與支線挑戰，像是完全不被發現、特定道具擊殺或限時達成，使得遊戲過程更具重複遊玩價值。

在市場評價方面，獲得相當兩極的反應。日本方面，《Famitsu》給予29/40的評分，肯定重現經典暗殺風格與Wii體感操作的創新表現，但也指出操作不夠流暢、鏡頭調整略為生硬，體感操作在激烈戰鬥中容易誤判，影響整體節奏與手感。不過許多日本玩家依然喜歡它濃厚的和風忍者氛圍與殘酷寫實的暗殺演出。

在歐美市場，評價相對偏向中下。IGN給出6.5分，認為雖然保有系列潛行暗殺的魅力，但受限於Wii的體感操作限制，導致動作反應不夠準確，鏡頭與操控設計不夠現代化，加上劇情演出稍嫌過時，整體表現未能達到系列過往水準。GameSpot則給予6分，認為氣氛營造與暗殺手法仍具特色，但流程節奏緩慢、敵人AI過於呆板、環境互動性不足，使得潛行過程缺少挑戰性與變化。

儘管評價褒貶不一，仍被部分老玩家視為難得的經典忍者潛行動作作品，特別是在Wii平台缺乏硬派潛行遊戲的情況下，提供獨特的沉浸式忍者體驗。對於喜歡和風題材、殘酷潛行暗殺與戰國陰謀故事的玩家而言，依然是不容錯過的特色作品。

Tenchu 4 (てんちゅう4), developed by Acquire and published by FromSoftware, is a stealth action game that was first released for the Wii platform in 2008. It serves as a direct continuation of the classic stealth-assassination Tenchu series and marks the franchise's debut on the Wii. The game maintains the series’ core ninja stealth mechanics while incorporating the Wii’s motion controls, offering players a more intuitive, physical way to experience assassination and stealth gameplay.

The story is set in a fictionalized version of Japan's Sengoku period and follows two main ninja characters, Rikimaru and Ayame, both of whom serve their lord, Lord Gohda. Their mission is to protect their master and preserve peace. The narrative begins with Rikimaru being tasked to investigate a mysterious disappearance, which gradually reveals a dark plot involving rebellion, sinister conspiracies, and supernatural forces. Ayame, early in the story, suffers severe injuries during a mission and is captured and brainwashed by enemy forces, even turning against Rikimaru. As the story unfolds, the destinies of the two characters intertwine, and players take turns controlling both ninjas, uncovering the secrets of the shadowy powers at play and ultimately working to prevent the nation’s downfall.

In terms of gameplay and mechanics, Tenchu 4 makes full use of the Wii Remote and Nunchuk’s motion control features. Players move and control the camera using the Nunchuk, while assassinations and attacks are performed by swinging or pointing the Wii Remote. When approaching an enemy from behind, an on-screen prompt appears — the player presses a button and simultaneously makes a swinging motion to execute one of several stylish, often brutal assassination techniques. These animations vary based on the angle of approach and the type of ninja tools employed. The game also introduces a “Ninjutsu Tool” and “Environmental Assassination” system, where players can use smoke bombs, poisoned needles, traps, and environmental elements like rooftops, rivers, and bushes to stealthily eliminate enemies, hide bodies, or create ambushes, enhancing the strategic element of stealth gameplay.

Another notable feature is the “Fear System”, where continuous assassinations and intimidation tactics raise the enemies' alertness and fear levels. When fear reaches its peak, enemies may flee or refuse to fight, adding a psychological edge and sense of control to the stealth experience. The game also offers various mission objectives and optional side challenges, such as completing a level without being spotted, using specific tools for a kill, or finishing within a time limit, adding replay value and difficulty variety.

On the market reception side, Tenchu 4 received mixed reviews. In Japan, Famitsu awarded it 29/40, praising its faithful recreation of classic assassination gameplay and innovative use of Wii motion controls, though noting issues with sluggish camera control, somewhat stiff handling, and occasional misreading of motion inputs during intense combat, which disrupted gameplay flow. Nevertheless, many Japanese players appreciated the game’s deeply atmospheric, Japanese-themed setting and its brutally realistic assassination animations.

In Western markets, the response was more lukewarm. IGN rated the game 6.5, recognizing the enduring appeal of its stealth assassination core but criticizing the limitations imposed by the Wii’s motion controls. The imprecise action detection, outdated camera and control designs, and an old-fashioned presentation meant the game fell short of the standards set by earlier entries in the series. GameSpot gave it a 6, acknowledging the atmospheric tension and varied assassination methods but pointing out issues such as slow pacing, simplistic enemy AI, and a lack of interactive environmental elements, making stealth missions less challenging and dynamic.

Despite the divided reception, Tenchu 4 is still regarded by some long-time fans as a rare and memorable stealth ninja experience, especially since the Wii platform lacked many hardcore stealth games. For those drawn to Japanese-themed settings, dark assassination stories, and the intricate conspiracies of the Sengoku era, it remains a distinctive title worth experiencing.