Pengo (Arcade)

Pengo
Developer: Coreland Publisher: Sega Platform: Arcade (custom) Released internationally: 1982 This game has hidden developer credits. This game has unused graphics. This game has unused music. This game has revisional differences.

Pengo is a Swiss stop-motion children's television series penguin who kills Sno-bees by crushing them with ice blocks.

Sometimes he'll crush the ice blocks too.

Unused Graphics

Animations for the Pengos and Sno-bees in the intro walking away from the screen. All the Pengos and Sno-bees have sprites dedicated to all of their angles in various sizes, but some of these angles aren't used.

As present in the game, the intro shows the two groups moving south while occasionally turning to show side angles, but never do they fully turn to show their backs. It's possible the path they took were once more sophisticated.

The last four levels of depth are used for the Pengos and Sno-bees until they reach a certain distance on the intro before swapping to the front and side-facing sprites.

One of Pac-Man's sprites, the sixth frame of his death animation, can be found within the game's graphic banks. This is the only remnant of Pengo being built off of Pac-Man's hardware.

(Source: Original TCRF research)

Unused Music

In Sets 1 and 3 (see below), this track is played during the maze drawing sequence. It's unused in sets 2 and 4.

(Source: Original TCRF research)

Hidden Credits

A hidden credits screen can be seen by holding Up and Button 1 for both players, then pressing 1P Start.

(Source: Sega Retro)

Other Developer Text

Two other chunks of developer text can be found in the main CPU. The first starts at 0x251C:

SNO-BEE DISPLAY BY NAKAKUMA AKIRA

(Source: Original TCRF research)

The second begins at 0x4D00 and gives credit to a fourth staff member. Note that each line is repeated 48 times!

1982:9:1 JAPAN :NOBUO KODERA : :TSUTOMU IWANE : :AKIRA NAKAKUMA: :SHINJI EGI :

(Source: Digital Press - Dave Widel)

Revision Differences

	Set 1C	Set 2	Set 3	Set 4
Test Menu Bug	Yes	No	No	No
ACT or RD	ACT	RD	RD	RD
High Score Default	20,000	0	20,000	0
High Score Name	AKIRA	MMIZU	MMIZU	MMIZU
Demo Version	Old	New	Old	Old
Curtain Speed	Slow	Fast	Slow	Slow
Maze Drawing Speed	Slow	Instant	Slow	Instant
Main Theme	Old	New	Old	New
Game Flow Changes	None	All	None	Some

There are four distinct versions of Pengo in the MAME romset: Set 1 revision C, Set 2, Set 3, and Set 4. The chronological order seems to be this:

• Set 1C
• Set 3
• Set 4
• Set 2

Most Sega-published home versions of the game appear to be based on Set 1C, retaining the ACT text and maze drawing sequences, although they usually replace the main theme with a unique song.

Test Menu Bug

In Set 1C, the test mode's dip switch display will not properly track the number of points needed for a bonus life. Fixed in all other sets.

ACT or RD

In Set 1C only, each stage is referred to as an ACT. For whatever reason, this was changed to RD in all other sets.

Default High Scores and Names

Set 1C	Set 3	Set 2+4

Sets 2 and 4 changed the default high score from 20,000 to 0.

Set 1C's default high score names spell out "AKIRA" vertically, the name of the game's programmer. All other sets list a "MMIZU", who might be a different member of the staff, but that name doesn't come up in the game's code at all.

Note that in Sets 2 and 4, the formatting of "RD" was changed from " RD" to "RD ".

Demo Version

Strangely, the competently played demo from the other 3 sets was altered in Set 2 so that Pengo dies almost immediately.

Curtain Speed

This is the speed of the curtain before each level. This was sped up in Set 2 so that it only lasts for a few frames.

Maze Drawing Speed

Sets 1 and 3 will take a few seconds to draw the maze before each level starts.

This sequence was removed in Sets 2 and 4, where the maze is set up almost instantly.

Main Theme

Old	New

Probably the most significant difference. In Set 1C and 3, the main theme is an 8-bit version of the song "Popcorn".

This was changed in Sets 2 and 4 to an original track, most likely due to copyright issues. This new track would later be used in the Atari 2600 and 5200 releases, alongside being remixed for the Game Gear version.

While the newer track is longer, the old track has a feature that the new track doesn't: When time is running out, the music will speed up.

Game Flow Changes

Set 4 introduced a number of changes to make the game flow faster than in previous sets.

• Number of frames before the level completion time is shown changed from 32 to 8.
• Number of frames after a time bonus is calculated changed from 128 to 64.
• Number of frames before the screen wipes after the player has died changed from 128 to a single frame.

Additional changes were made in Set 2:

• Delay before player can move at the start of a stage changed from 64 frames to 16 frames.
• Delay before the next level loads after an intermission changed from 64 frames to 16 frames.
• Delay before the sky rapidly changes colors in the intro changed from 64 frames to 48 frames.

(Source: Original TCRF research)