《快打旋風4》（STREET FIGHTER IV）是Capcom於2008年推出的格鬥遊戲，該系列在沉寂多年後重返市場。以3D建模結合2D平面格鬥的方式呈現，保留經典的格鬥玩法，同時加入全新的系統與角色，帶來創新的戰鬥體驗，並為格鬥遊戲界帶來全新的活力。

劇情時間線位於《快打旋風2》與《快打旋風3》之間，主要圍繞著名為S.I.N.的神秘組織展開。這是影羅（Shadaloo）殘黨所建立的新勢力，領袖為賽斯（Seth），是影羅基因實驗創造出的改造人，具備模仿他人招式的能力。賽斯舉辦新的世界格鬥大賽，目的在於吸引強者參賽，以收集數據，完成他的終極武器「Tanden Engine」。然而，隆（Ryu）的「殺意波動」力量成為賽斯最感興趣的目標，引發一連串的對抗與衝突。

主要角色方面，除保留經典角色陣容外，還加入多名新角色，使得整體角色陣容更為多元。經典角色如隆（Ryu）、肯（Ken）、春麗（Chun-Li）、豪鬼（Akuma）、古烈（Guile）等悉數回歸，滿足老玩家的情懷需求。新角色方面，則有：

賽斯（Seth） – 本作的最終BOSS，影羅的改造人，能模仿其他角色的必殺技，是極具挑戰性的對手。

深紅毒蛇（Crimson Viper） – 神秘的女特工，擅長使用電擊與火焰攻擊，速度極快且操作多變。

阿貝爾（Abel） – 遺失記憶的法國摔角格鬥家，擅長投技與近戰，背景與影羅實驗有著千絲萬縷的聯繫。

艾爾·弗爾特（El Fuerte） – 墨西哥摔角手，戰鬥方式結合摔角與快速移動攻擊，風格極具娛樂性。

魯弗斯（Rufus） – 體型巨大但行動敏捷的美國格鬥家，一心想擊敗肯證明自己才是美國最強。

這些角色的加入，使得格鬥舞台更加豐富，每位角色的個性與戰鬥風格截然不同，能夠在選擇角色時體驗多樣的格鬥方式。保留《快打旋風2》的核心格鬥系統，如波動拳、昇龍拳等標誌性技能都得到延續，並在此基礎上進行大幅強化與革新。動作更加流暢且具有立體感，同時保持經典的橫向戰鬥方式，確保傳統玩家能夠快速上手。遊戲系統方面，引入「集氣技」（Focus Attack）系統。這是全新的防禦與反擊手段，在集氣過程中吸收一次攻擊，並反擊對手。這項技能強調攻防轉換的重要性，使比賽更加緊湊且富有戰略性。

此外，「超必殺技」（Ultra Combo）是另外亮點。當角色受傷累積到一定程度後，「超必殺技槽」將會蓄滿，此時可以施放威力極大的終極技能，進行逆轉攻擊。這項系統讓比賽更具戲劇性，即便處於劣勢，也能透過精準操作反敗為勝。關於操作性，延續簡單易懂的按鍵輸入模式，讓新手能快速入門。然而，對於進階玩家而言，進階連段與防禦反擊系統則需要大量練習與技術積累，保留格鬥遊戲的技術深度。

關卡場景遍布全球，每位角色的場景背景都設計得極具特色。例如，隆的場景位於日本的傳統寺廟，肯的場景則設定在美國都市街頭，春麗的場景為中國市場，這些場景不僅視覺效果出色，還營造出濃厚的地域氛圍，讓玩家仿佛置身於世界格鬥大賽的舞台。有街機模式、挑戰模式與對戰模式。街機模式中，需擊敗一連串對手，最終挑戰賽斯；挑戰模式則針對連段與特定招式進行訓練，幫助玩家提升技術；對戰模式則支持本地與線上玩家對戰，可以隨時挑戰全球對手。

推出後獲得極高的市場評價與銷量，許多評論認為它成功重現該系列的經典魅力，並進行合理的創新，為格鬥遊戲的復興奠定基礎。整體的打擊感、角色平衡性與流暢度都受到業界與玩家的高度肯定，並且成為當年各大格鬥遊戲比賽的熱門項目之一。玩家普遍認為，作品既保留系列經典的格鬥元素，又融入現代遊戲設計理念，使得它在吸引新玩家的同時，也讓老玩家找回當年街機格鬥的激情。然而，部分玩家對於賽斯這個BOSS的難度設計抱有爭議，認為他過於強大且攻擊模式不公平，但這也成為玩家挑戰自我的一部分。

總體而言，《快打旋風4》在遊戲歷史上佔有重要地位，成為格鬥遊戲復興的重要里程碑，其後續的增強版與資料片進一步擴展遊戲內容，持續吸引著全球玩家，為該系列開創全新的篇章。

Street Fighter IV is a fighting game developed by Capcom, released in 2008, marking the franchise’s return to the market after years of dormancy. The game combines 3D character models with 2D plane fighting, preserving the classic fighting gameplay while introducing new systems and characters. This innovative approach revitalized the fighting game genre, injecting fresh energy into the scene.

The storyline is set between Street Fighter II and Street Fighter III, revolving around a mysterious organization called S.I.N., an offshoot of Shadaloo. The leader, Seth, is a bio-engineered creation from Shadaloo’s experiments, capable of mimicking other fighters' techniques. Seth organizes a new World Warrior tournament to attract powerful fighters and collect data to complete his ultimate weapon, the “Tanden Engine.” Ryu’s “Satsui no Hado” (Surge of Killing Intent) power becomes Seth’s primary target, triggering a series of confrontations and conflicts.

In terms of characters, the game retains a roster of classic fighters while introducing new faces, creating a more diverse selection. Iconic characters such as Ryu, Ken, Chun-Li, Akuma, and Guile return to satisfy veteran players. New characters include:

Seth – The game’s final boss, a bio-engineered fighter from Shadaloo capable of copying other characters’ moves, presenting a formidable challenge.

Crimson Viper – A mysterious female agent skilled in using electric and fire-based attacks, known for her speed and versatile combat style.

Abel – A French grappler with amnesia, proficient in throws and close combat, with deep ties to Shadaloo experiments.

El Fuerte – A Mexican luchador whose fighting style blends wrestling and swift mobility, offering a highly entertaining and dynamic playstyle.

Rufus – A large yet agile American fighter obsessed with defeating Ken to prove himself as the strongest fighter in the U.S.

The addition of these characters enriches the combat experience, with each fighter bringing unique personalities and fighting styles to the stage. Classic mechanics from Street Fighter II, such as the Hadouken and Shoryuken, return and are refined with enhanced visuals and smoother animations, preserving the traditional side-scrolling combat style for easy pick-up by returning players.

The game introduces the Focus Attack system, a new defensive and counter mechanism allowing players to absorb an attack during the charge-up and strike back. This feature emphasizes the importance of offensive and defensive transitions, adding a strategic layer to battles.

Another highlight is the Ultra Combo system. As fighters take damage, their Ultra Combo gauge fills, enabling them to unleash powerful finishing moves. This mechanic introduces dramatic reversals, allowing players to stage comebacks even when at a disadvantage.

Street Fighter IV maintains simple and accessible button inputs, ensuring quick learning for newcomers. However, advanced players can explore complex combos and counter techniques, preserving the game’s depth and rewarding dedicated practice.

The game’s stages span the globe, with each character’s background reflecting their origins. For example, Ryu’s stage is set in a traditional Japanese temple, Ken’s in an American urban street, and Chun-Li’s in a bustling Chinese market. These visually striking environments enhance the immersive experience, capturing the essence of a world fighting tournament.

Game modes include Arcade Mode, Challenge Mode, and Versus Mode. In Arcade Mode, players face a series of opponents, culminating in a battle against Seth. Challenge Mode focuses on honing combos and specific moves, while Versus Mode allows for local and online multiplayer battles, enabling players to compete globally at any time.

Upon release, Street Fighter IV received widespread critical acclaim and commercial success. Many reviews praised its successful revival of the series’ classic appeal, coupled with thoughtful innovations that laid the groundwork for a fighting game renaissance. Its satisfying hit detection, character balance, and fluidity were highly praised, making it a staple in major fighting game tournaments.

Players lauded the game’s ability to blend nostalgic elements with modern design, attracting new audiences while rekindling the excitement of arcade-era veterans. Some players, however, criticized Seth’s difficulty, arguing that his moveset was excessively powerful and unfair. Yet, this challenge became part of the game’s allure for those seeking to test their skills.

Overall, Street Fighter IV holds a significant place in gaming history, serving as a cornerstone in the fighting game resurgence. Its enhanced versions and expansions continue to draw players worldwide, ushering in a new chapter for the beloved franchise.