《式神之城III》（日文名：式神の城III，英文名：Castle of Shikigami III）是由Alfa System開發、由Arc System Works在日本發行的縱向捲軸射擊遊戲，原本為街機平台作品，後於2008年移植至Wii與Xbox 360平台。是「式神之城」系列的第三作，延續一貫的「彈幕射擊」（bullet hell）風格，並以濃厚的奇幻與現代都市傳奇題材為背景，將劇情與高速射擊緊密結合，是融合東方神祕與科幻風格的動作射擊遊戲。

在劇情方面，故事發生於現代都市與神祕異能共存的世界，背景設定在日本近未來的首都「東京新都」。主線圍繞著連續發生的異常事件與「式神」的暴走現象展開。將操作多位擁有特殊能力的角色，這些角色與「式神」簽訂契約，能夠召喚或操控式神來進行戰鬥。每個角色都有其獨立的背景故事與動機，有些人為尋找失蹤的親人，有些人則肩負對抗邪惡組織的使命。採用多重視角敘事，根據所選角色的不同，劇情發展與對話也會有所變化，甚至出現多重結局與分支劇情，這點在傳統射擊遊戲中相當少見，也成為本作的一大特色。

最多支援兩人同時遊玩，可從10位角色中選擇，每位角色皆配有兩種攻擊模式與一種「式神」技，並具備截然不同的操作感與射擊風格。操作上，延續系列傳統，核心玩法建立在「近距離攻擊加分」的機制，也就是當玩家的機體靠近敵人或子彈時會觸發得分加乘與特殊效果，不僅要躲避彈幕，更要主動接近危險區域來獲取高分，營造出高風險高報酬的緊張節奏。

Wii版本的操作則充分利用Wii Remote與Nunchuk的結合，雖然仍可使用傳統控制器操作，但Wii特有的體感操作也支援部分功能，如瞄準與選單操作等。畫面方面，則在原本的2D彈幕射擊基礎上加入3D背景與轉場特效，使整體視覺更具立體感，同時保持彈幕的密度與視覺衝擊力。角色造型由知名插畫家「伊藤龍馬」負責，維持系列獨特的日式幻想風格，而角色語音方面則提供完整的日文語音配音，並在美版中加入英語字幕。

在市場評價方面，屬於評價兩極的作品。對於熱愛彈幕射擊與系列作品的老玩家來說，提供極具挑戰性的關卡設計、多樣化的角色操作手感與可重複遊玩的劇情分支，是內容紮實的射擊遊戲。尤其是近身得分機制與雙人合作模式，被認為是提升耐玩度的關鍵。

然而，對於較不熟悉此類型或初學者來說，其高難度、畫面混亂（尤其是滿屏彈幕時）與缺乏新手教學，會讓人感到挫敗。Wii版本雖增加便利的操作選擇，但也因解析度與控制反應略遜於Xbox 360版本而受到部分批評。劇情方面，雖然有豐富角色互動與多線敘事，但英文翻譯品質在歐美版本中曾被批評為生硬甚至有錯誤，影響部分玩家的劇情體驗。

總體來說，這是極具特色的日式彈幕射擊遊戲，在傳統街機射擊架構下融入濃厚劇情與角色養成元素，對射擊遊戲迷與系列粉絲而言極具吸引力。不僅在彈幕美學上達到視覺與操作的極限挑戰，也在角色設計與世界觀構築上展現出濃厚的日式幻想風格。雖然不屬於主流市場的大眾作品，但對於尋找傳統街機射擊魂的玩家來說，是值得收藏與深入體驗的佳作。

Castle of Shikigami III (Japanese: 式神の城III) is a vertically scrolling shoot-'em-up game developed by Alfa System and published in Japan by Arc System Works. Originally released as an arcade title, it was later ported to the Wii and Xbox 360 platforms in 2008. This is the third installment in the Shikigami no Shiro series, continuing its signature "bullet hell" gameplay while fusing modern urban legends and fantasy themes, blending fast-paced shooting action with a rich narrative steeped in mysticism and sci-fi elements.

The story takes place in a near-future version of Tokyo called "Shin Tokyo," where the ordinary world coexists with supernatural abilities. The main plot follows a series of mysterious incidents and violent outbreaks involving "Shikigami," spiritual beings bound to human summoners. Players control various characters, each with their own supernatural abilities and personal motivations — some searching for missing loved ones, others battling against sinister organizations. The game employs a multi-perspective narrative, where the story progression and dialogues shift depending on the chosen character, featuring branching storylines and multiple endings — a rare and notable element for a genre typically focused on pure action.

Supporting up to two players in simultaneous play, the game offers ten selectable characters. Each has two different attack styles and a unique "Shikigami" technique, offering distinct playstyles and tactical options. Castle of Shikigami III continues the series' hallmark gameplay mechanic: the "proximity scoring system." By intentionally bringing the player's character dangerously close to enemy bullets and foes, players can earn score multipliers and trigger special effects, rewarding risk-taking with higher scores. This creates a tense, high-risk, high-reward gameplay loop where dodging isn't enough — aggressive, close-quarters play is encouraged.

The Wii version takes advantage of the Wii Remote and Nunchuk setup. While traditional controller support remains, the Wii’s motion controls add optional functionalities such as aiming and navigating menus. Visually, the game enhances its 2D bullet patterns with 3D backgrounds and cinematic transitions, adding a sense of depth without compromising the screen-filling barrage of bullets. Character illustrations by renowned artist Ryoma Ito maintain the series’ distinct Japanese fantasy aesthetic, while full Japanese voice acting is included, with English subtitles provided in the Western release.

Reception for Castle of Shikigami III has been mixed. Enthusiasts of bullet hell shooters and longtime fans of the series praised its challenging stage designs, diverse character mechanics, and replayable branching storylines. The proximity scoring system and cooperative play mode were particularly highlighted as features that increased replay value. However, for newcomers unfamiliar with this genre, the steep difficulty curve, screen-flooding bullet patterns, and lack of comprehensive tutorials were frequently cited as barriers to entry. The Wii version, while offering convenient control options, received criticism for its lower resolution and slightly less responsive controls compared to the Xbox 360 version.

The narrative, while rich with character interaction and multi-threaded storytelling, was met with mixed reactions in its Western release due to awkward and occasionally inaccurate English translations, which hindered the experience for some players.

Overall, Castle of Shikigami III stands as a unique and distinctive bullet hell title. It marries traditional arcade shooter mechanics with a narrative depth uncommon in its genre, incorporating character progression, dense lore, and elaborate world-building. Though niche and challenging, it remains a rewarding experience for hardcore shooter enthusiasts and fans of Japanese fantasy worlds, delivering visually mesmerizing bullet patterns and complex gameplay systems. For those seeking a retro-style arcade shooter with deep character stories and intense gameplay, this is a title well worth adding to any collection.