Let's ignore that game, and I want to know what the lowest win percentage for a "normal" game is.
The original Bullseye game where you had to guess the exact price of the car within 7 attempts. Its win percentage was 0%. Yeah. It was literally never won. Of course, considering it didn't last long, that probably wasn't the answer you were looking for.
As for current games with the lowest win percentages, I'd have to guess Golden Road, Pay the Rent, 3 Strikes, and Triple Play (in no particular order, though I think Triple Play has the lowest considering we had to wait like 7 years before we got another daytime win on that game, and then another full year before the next win (both were around Christmas 2015 and 2016 respectively). Golden Road hasn't been much better, but at least it did produce that Mercedes-Benz S550 win during Dream Car Week 2016 plus that other Mercedes-Benz win from the end of 2014. Pay the Rent has had tons of winners if you consider winning anything to be a win, but only three people have ever fully won the game (i.e., won the $100,000), and if I remember correctly, those three people only won because they had relatively easy setups (but then again, Pay the Rent still hasn't been around as long as the time we had to wait for that Triple Play win in 2015). I'd say 3 Strikes actually has the highest win rate of the four games I've described, but it still hasn't had a good record. It did start season 44 with two wins in a row ($49,752 Audi A3 Cabriolet sometime in September and $56,174 Mercedes-Benz Roadster SLK300 in December), and just this last October, there was that epic comeback with that $63,415 Cadillac. So I'd say in order from highest to lowest win percentage (of the four games described above), it would be the following:
3 Strikes
Golden Road
Pay the Rent
Triple Play
I couldn't tell you the definitive order, though. The order I listed was only based on my guess. Of course, there are some other honorable mentions: That's Too Much!, Stack the Deck, Lucky $even (questionable though considering how often the producers manipulate this game), and recently (at least from what I read) Master Key.