I've gotten over 7000 now but all I've seen are the dark cyan robots. According to Wikipedia:
Two different versions of the game were released. In the original version, the sequence goes as follows:
Dark yellow robots that do not fire
Red robots that can fire 1 bullet (500 points)
Dark cyan robots that can fire 2 bullets (1,500 points)
In this version of the game, after 5,000 points, Evil Otto doubles his speed, moving as fast as the player while robots remain in the maze, and twice as fast as the player after all the robots are destroyed.
The revised version, which had the much larger production run of the two, features a longer color sequence after the cyan robots:
Green robots that fire 3 bullets (3k)
Dark purple robots that fire 4 bullets (4.5k)
Light yellow robots that fire 5 bullets (6k)
White robots that fire 1 fast bullet (7.5k)
Dark cyan robots that fire 2 fast bullets (10k)
Light purple robots that fire 3 fast bullets (11k)
Gray robots that fire 4 fast bullets (13k)
Dark yellow robots that fire 5 fast bullets (15k)
Red robots that fire 5 fast bullets (17k)
Light cyan robots that fire 5 fast bullets (19k)
At first I thought I was using the wrong set, but I double-checked my setup and the Game Information in MAME and I'm definitely on set 2. I don't see any dip switches that would change this. Any thoughts on what might be going on?
Thanks.