Viper Phase 1

Viper Phase 1

Title screen

Developer:	Seibu Kaihatsu
Music:	Go Sato
Program:	Yoritaka Kasai
Art:	Toshinobu Komazawa
Release date:	May 1995 (Japan)
Previous game:	Raiden DX
Next game:	Raiden Fighters

Viper Phase 1 is a 1995 vertically scrolling shooter video game developed by Seibu Kaihatsu for arcades. Often regarded as a spin-off or spiritual successor to the Raiden series, the game shares many similarities in terms of gameplay mechanics and design. Viper Phase 1 is the first game developed for Seibu Kaihatsu's SPI system board, featuring detailed sprite-based graphics and elaborate explosion effects.

The initial release (now known as Old Version) failed to gain acceptance among many players due to its unorthodox weapons system. Three months later, a revised New Version was released, featuring adjustments that brought the gameplay closer to Raiden, such as making sub-weapons permanent. This version also formed the basis for overseas releases of Viper Phase 1.

Hamster Corporation released the game as part of their Arcade Archives series for the Nintendo Switch, PlayStation 4, and PlayStation 5 in December 2024.

For replay videos, visit the Video Index.

Gameplay Overview

The game consists of eight stages and supports two-player simultaneous play. There are no extends.

Controls

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• 8-way joystick: Moves the player's craft.
• A: Simultaneously fires the player's main weapon and sub-weapon.
• B: Activates the player's bomb. There is a slight delay before the bomb detonates.

Weapons

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Sub-weapons can be equipped by destroying a weapon carrier craft and picking up the weapon change item it drops. Weapon carriers generally appear in sync with specific enemy ships during the stages and can also appear during boss battles. Weapon change items float down the screen oscillating right and left and changing their weapon type every time they change direction. The starting weapon type is random, but the cycle order is fixed as Wide, Laser, Missile, Napalm, Wide, Laser... and so on.

Icon	Name	Function
	Wide	The recommended weapon for the entirety of the game. Fires shots in a fan-shaped pattern covering a wide area. Powering up expands the firing range. While the damage per individual shot is low, point-blanking enemies unleashes devastating attack power.
	Laser	Fires a laser beam straight ahead. Although the effective range is narrow, the weapon is powerful. Powering up increases the thickness of the beam. This weapon is effective against heavily armored enemies.
	Missile	Launches missiles across a wide area in front of your ship. The missiles travel slowly but explode upon impact, dealing massive damage. Powering up increases the number of missiles fired and expands the size of the resulting explosions.
	Napalm	Fires missiles straight ahead from both wings of your ship. They detonate upon impact, dealing concentrated, high-damage hits. Powering up increases the number of explosions generated by each missile, allowing the blast to cover a wider area.

Items

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Destroying item carriers that appear at predetermined points throughout each stage will release either a power-up item or a bomb item. These items appear in a repeating power-up, power-up, bomb, power-up, power-up, bomb... sequence with every item carrier destroyed.

Medals can be revealed by destroying various airborne and ground-based targets.

Icon	Name	Function
	Power-up	Upgrades both the main weapon and sub-weapon shot power up to a maximum of three levels. However, if you choose the Laser or Napalm sub-weapon, your main shot is downgraded to its weakest form. In Old Version only the main weapon is upgraded.
	Bomb	Increases the player bomb stock by 1.
	Small medal	Worth 500 points, or 2,000 points at max value.
	Large medal	Worth 1,000 points, or 3,000 points at max value.
	Special medal	Worth 30,000 points, or 100,000 points at max value. Can be revealed twice in the game.

Rank

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If the game features a relevant rank system, use this section to discuss it in more detail. Otherwise, this can be omitted.

Loops

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Scoring

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This section should cover a general breakdown of the scoring system of the game. Feel free to put the meat and potatoes here. A great example of a scoring section is the DoDonPachi page.

Strategy

See (Template Page)/Strategy for stage maps, enemy and boss descriptions, walkthroughs, and advanced play strategies.

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This section details some particular strategic information about the game and its gameplay, such as hidden 1UPs and some basic scoring tricks. For anything particularly deep or highly complex, you can probably leave it in the Strategy page.

(Currently evaluating whether or not this specific section should even include information outside of the separated Strategy pages. Worth thinking about as a community.)

Story

The year is 2050 (Cosmic Era), long after humanity embarked on a massive space colonization project in search of a "second Earth." Having settled across various star systems, humanity developed unique cultures and scientific advancements, yet simultaneously fell into conflict, sparking a succession of large-scale interstellar wars. The flames of war eventually reached Earth itself; a rebel force from another star system—possessing technology far superior to Earth's—brought a massive fleet led by a space aircraft carrier into Earth's orbit and demanded unconditional surrender. In response, the Earth Defense Force launched a top-secret operation codenamed "Viper Phase 1," the plan for which was to infiltrate the enemy carrier, gather data, seize a new type of enemy fighter, and then use that fighter to destroy the carrier.

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Development History

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Version Differences

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Trivia

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Gallery

See (Template Page)/Gallery for our collection of images and scans for the game.

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Other

We have support for wikitables, giving us the potential to add lots of cool info in a small box on the page somewhere, but we are not using them at the moment. I'm just leaving this here so we can have it handy in case we decide to actually use them. Feel free to not use this section.

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