Quoted from Pdxmonkey:How do you get to Springfield mystery spot?
Read the rule sheet by Bowen Kerins, it's great:
http://www.ipdb.org/rulesheets/4674/tspp-rulesheet.txt
A short quote from the rule sheet:
When all ten double scoring modes have been completed (and are not running),
the red lights will pulse instead of being solidly lit. Then, shoot the
Otto shot one more time to start...
--- SPRINGFIELD MYSTERY SPOT ---
"Where logic takes a holiday and all laws of nature are meaningless." Boy,
you'd better believe it, because the left flipper button and the right
flipper button have switched their abilities. "Everything's all backwards!"
-Brannon