As always when you design a pinball machine there are a lot of things that never make it to the final product.
These are the words of the designer Brian Eddy:

"AFM was the most different. It had one big feature that didn't make it into the game. The saucer in the middle of the playfield was originally suppose to move out and around the playfield.
It started (rested) right where the static one on the final game is. It had a telescopic arm that allow the
saucer to move out about 18 inches onto the playfield and a pivot that would rotate it right & left.
So it basically could "move" around the whole playfield (hence the open playfield area in the final design).
It also had a target hanging down from the middle of the saucer that you could shoot from
any angle. We ran out of time to develop it and keep it cost effective.
It was also a reliability issue and to make it rock solid would have required a lot of testing time.

The Martians also started out like the string push toys (you push the bottom of a platform and they
jiggle/collapse). When you would hit them they would fall to pieces. We couldn't make it reliable (String would always break to soon) so we found this really flexible plastic and made them jump up/down.
Not quite as effective but still a lot of fun to watch and very reliable."

The prototype motherships had a clear dome (green on the production ships) and a lighter shade of grey.

The six smaller spaceships on the playfield should initially have 8 LEDs around the flasher dome but this idea was too expensive.
The mold for these ships was already made so the holes for the LEDs are still there.
A kit to remake this cool light effect can be bought at UFOPinball.

The Video Mode has been programmed by designer Brian Eddy himself and the idea is taken from an old
computer game called "Sabotage".

See artist Doug Watsons´ pictures of the original backglass painting and Martian sculpture on his website.
Doug Watson is also the voice talent used for the Martians.

Below are some questions answered by Brian Eddy:

What did you do to get inspiration for the design? Did you watch any Sci-Fi
movies from the 50´s?

Yes, I watched a TON of very bad 50's movies to get "in the mood" and pick
up on the whole era. Some were really really bad but all had that 50's
flavor so they were great reference. Movies in general were a lot slower
moving back then. I bought just about every cheesy movie I could find. Most
of them were so bad they were funny. I think 4 of them were actually pretty
good (Forbidden Planet, War of the Worlds, The day the earth stood
still,EARTH VS THE FLYING SAUCERS).

The movie "Mars Attacks" was released about the same time as AFM.
Was AFM a way to get around the license costs
related to movie tie-ins, or was it just a coinsidence? The Martians have
some common features...

Not related at all. The Mars Attacks trading cards from the 50's were a good
reference but we didn't know about the movie until the game was close to
done. Hollywood always has thousand of movies in the "possible" stage at
anytime. We knew the trading cards were being shopped as a movie idea but
never thought it would actually get picked up and made. It was and the
timing was good for us but the game didn't have anything to do with the
movie other than they were both based on the cheesy Sci-Fi movies of the
50's. The Martians are a combination of all the Martians from movies during
the 50's and actually look a lot closer to one of the movies from the
50's(can't remember the name). So just a coincidence...but a good one on our
part because we did of course catch some of the hype from it and
Independence Day.
 

For more Brian Eddy, please read my interview with him here.

The AFM Design Team was one of the seminar guests at Pinball Expo 2004. Read more in Pinball News´article.