Divoc-91

This game is inspired by Gyruss, an arcade game designed by Yoshiki Okamoto and released by Konami in 1983.

Introduction

In the era of Covid-19, scientists finally found a vaccine against the virus and called it Divoc-91. Now it's up to you to guide the vaccine, in the form of a blue sphere, into the human body and eliminate the virus that infects it.

Gameplay

The majority of enemies are virions, which must be killed to complete a stage. They appear either from the center of the screen or from one of the edges, and move in swirling patterns. They can shoot the player's vaccine sphere or destroy it by contact. They hover near the center of the screen after completing their deployment pattern, and occasionally move outwards and shoot at the player. If not killed by the player, the virions gradually move away one by one.

There are also several other types of enemies: microbes, antibodies, and bacteria. These appear intermittently and soon disappear of their own accord if not killed by the player. Microbes appear in a group of three from the center of the screen on the opposite side of the player after the ordinary virions have finished deployment. They move along a predetermined path and shoot at the player. If the player has the basic weapon when the microbes appear, in the middle of them is a flashing vitamin sphere. If hit, the player gets a better weapon. Antibodies fly straight outwards from the center of the screen at regular intervals. They cannot be killed, but a small points bonus is given for shooting at them. Flocks of bacteria occasionally appear from the center of the screen. They consist of 8 units moving rapidly along an elliptical path. Killing them all gives the player some extra points.

Every 3 stages a short bonus round is played, where the player can shoot enemies for bonus points without worrying about being destroyed by them. Each enemy destroyed in the bonus stage scores 100 or 10000 for all 40.

The player has to pass 24 stages to get rid of the infection completely. Then the game starts all over again at a higher difficulty level.

At 30000 points and then every 60000 points, the player earns an extra life.

Options

There are 4 difficulty levels to choose from: Normal, Hard, Expert, Master.

Controls

Arrow keys Controller lever	Move the vaccine sphere
Spacebar Ctrl keys Any controller button	Fire
P	Pause
Home	Stop game and return to title screen
Shift+Del	Reset ranking (while the top scores are displayed)
F10	Change pixel effect
F11	Toggle integer scaling
F12	Toggle fullscreen
Esc	Exit game

You can also use the WASD or IJKL keys as directional keys, and the Z or M keys as fire button.

The gamepad D-Pad can also be used.

History

Version 1.0

• First release.

Version 1.1

• In fullscreen mode, the game could be jerky using certain video cards.

Version 1.2

• You can now use the WASD or IJKL keys as directional keys.
• You can now use the Z or M keys as fire button.
• You can now use the gamepad D-Pad.
  

Version 1.3

• There are now separate score rankings based on the difficulty level you choose.
• You can now use the controller to enter a top score name.
  

Version 1.4

• More controllers are now recognized.