First-party prototype cartridges for Nintendo Entertainment System games are difficult to come across. For whatever reason, though, several distinct prototype versions of Nintendo’s 1990 puzzler Dr. Mario are known to exist.
Why is this the case? I have no idea. Frankly, it makes no damn sense whatsoever.
Originally titled “Virus,” the first discovered build, which has modified gameplay mechanics and a different cast of characters, turned up in Norway in 2008.
Recently, yet another version of Virus was included as part of an auction for a PlayChoice-10 arcade unit in Georgia. While it’s unusual that so many copies of a Japanese-developed, first-party Nintendo game have been discovered in the West, Lost Levels’ Frank Cifaldi notes that Nintendo-owned Chuck E. Cheese restaurants in the Seattle area were once used to playtest NES games during development, which might explain the existence of the PlayChoice-10 version, at least.
You can download the PlayChoice-10 version of Virus here.
Despite being later in development than previously discovered prototype versions, this copy of Virus has several differences from the retail version of Dr. Mario.
Both the title screen and the pre-game options menu are different. The music tracks aren’t yet named, and the speed setting is known as the “sick level.”
In Virus, a bonus counts down with every pill dropped, and it awards a point value after you clear the final virus from each level. This mechanic was removed prior to Dr. Mario’s release.
The virus characters are in an early state. They hang out in an oval (changed to a magnifying glass in Dr. Mario), and while they animate, they do not move in a circular motion, as they do in Dr. Mario.
Also, the yellow virus was redrawn for the retail release, because his nose totally looked like a penis.
Bring up the options screen for the two-player mode and you’re greeted with a familiar tune: it’s the menu music from Nintendo World Championships 1990! This track was also used in the Japan-only Famicom release Hello Kitty World. Nintendo was quite fond of that song, apparently.
Dr. Mario’s two-player win music isn’t yet implemented in Virus. Instead, the game uses the background music from Dr. Mario’s single-player intermission scenes. These scenes are not found in Virus.
Other differences Lost Levels members have noted:
– Mario’s sprite is different.
– The game keeps track of pills above the screen, so if you rotate them and one goes off the top, it’ll fall back down when there’s room.
– The highest levels allow pills up to the third line of the bottle, so you have to clear them horizontally (there’s no room).
– The background doesn’t switch colors to indicate difficulty level.
– The pill drop timer in hard mode is 10 frames in Virus, as opposed to 14 in Dr. Mario.
– Song A (“Fever”) is longer in Virus than it is in Dr. Mario.
– Two unused music tracks are present in the Virus ROM.
[Research credit: kap, kevtris, Skrybe, Xkeeper, ArnoldRimmer83, BMF54123]