Galaxy and other Sega games used several interesting mechanisms:
Slings that work via pressure from the ball hitting a large piece of plastic instead of ganged switches, and pop bumpers that are a single piece of plastic rather than using a rod and ring assembly. On top of that, Galaxy has an under-playfield magnet that will move the ball from left to right, similar to the Mist ball on Bram Stoker's Dracula.
Neat stuff!
http://ipdb.org/machine.cgi?id=979
Gameplay video:
https://youtu.be/bBFtqw0rKpY