To respond to the above posts, Blockbusters (Cullen version) did a similar finale, as they played the last game for $5,000. And what was described for the SP finale was also done on Password Plus. Instead of trying to get to an Alphabetics, they just played the main game till the end, and whoever was in the lead got $5,000. I might add that the one Alphabetics played on the PW+ finale came at the very beginning of the show ($12,000 of a $20,000 jackpot was won, BTW, because Tom Poston pantomimed using a "kite," and described "mammal" as "not fish"), so that was probably a lot of play time in the case of PW+.
IIRC, the last TTD ended with a win in the main game, not sure if they did or didn't get to play the bonus game (I was about to say no, but somehow I do remember them getting to do so)