A few nights ago I was playing in a Pinball Arcade tournament, on Space Shuttle (one of the 8 featured). This happened:
After finishing the game, I checked on the rules in-game and it only mentions that I can get 20,000 upon completion of the bank of drops. BUT it gave me 50,000 instead and a flasher sequence to pinpoint this. I also looked up the rules on the web but to no avail. I may have discovered a new rule in Space Shuttle that involves a Sweeping Bonus that was later implemented in games like Whirlwind.
This has me thinking: Are there any other games that have some hidden, undiscovered rules that might be interesting to find?