North American box art
Developer(s)	Jaleco
Publisher(s)	Jaleco
Composer(s)	Tsukasa Tawada
Platform(s)	Game Boy
Release	JP: February 26, 1991 NA: September 1991
Genre(s)	Run and gun/Multi-directional shooter
Mode(s)	Single-Player, Multi-Player

Fortified Zone, known in Japan as Ikari no Yōsai (怒りの要塞, Ikari no Yōsai, "The Fortress of Fury") is a 1991 video game developed and published by Jaleco for the Game Boy. It was first released in Japan on February 26, 1991 and later released in North America in September 1991. It was later added to the Nintendo 3DS's Virtual Console on July 7, 2011, but the Australia region had it added on July 28, 2011.

Fortified Zone's plot follows two Mercenaries named Masato Kanzaki and Mizuki Makimura as they infiltrate a literal fortified zone, where they must take on mercenaries, soldiers, robots and monsters before destroying the central complex at the fortified zone's heart.

Fortified Zone allows the player to switch between two characters during game play. Each character has their own strengths and weaknesses: Masato (the male mercenary) uses all the special weapons, but cannot jump. Mizuki (the female mercenary) can jump, but cannot use the special weapons. A top-down shoot-'em-up, the game had four multi-room levels, titled 'Field', 'Jungle', 'Caves' and 'Complex'. At the end of each level the player faces a 'boss' character: a cannon installation, a supertank, a dragon, a bulldozer and a large assault vehicle as the final boss. Items that can be picked up in gameplay include medical packs, flamethrowers, hand grenades, rocket launchers, 3-way machine guns and chain guns.

The game was the first entry in the Ikari no Yōsai series, and was followed by two sequels: Ikari no Yōsai 2 for the Game Boy (which was released only in Japan), and Ikari no Yōsai for the Super Famicom (released outside Japan as Operation Logic Bomb for the Super NES). The former was later re-released for the Japanese 3DS Virtual Console on January 11, 2012.

Super Gamer gave an overall score of 70% stating: "Original shoot-'em-up which is a bit too short to hold anybody in its grasp for long."^[1]

Survival of the Fastest, the debut album of Irish thrash metal band Gama Bomb features the song 'Fortified Zone' based on the game.

• Ikari no Yōsai and Ikari no Yōsai 2 at Jaleco (in Japanese)
• Fortified Zone at MobyGames