Sonic 06.
There most certainly are worse games out there that I know, but this is the worst I've ever played. This game is worse than Big Rigs: Over the Road Racing, because Big Rigs is laughably bad and I had actually had a fun time encountering the horrible designing in the game. It was extremely funny and to this day, I still think it is.
Sonic 06 however, is frustratingly bad. It's also probably the only game I've ever played that keeps on getting worse the more you play it. Every single aspect of this game, except for the music, is absolute stuff. What makes me even angrier is that people say that "if this game's glitches were fixed it would be a perfect game!!!!"
No. To all of you who DO think that:
What about Silver's ball puzzle? Was that a "glitch"? Did they accidentally mess up some coding and that's why the ball puzzle is there? No. Is the End of The World level a glitch? No it's not. Is every single god-awful gameplay style in this game a glitch? NO. People who say this game was only bad due to glitches are loving idiots. This game was designed horribly. The game was doomed from the start when they agreed to implement all these terrible ideas.
No game has ever made me as angry, frustrated and disappointed as Sonic 06. It is without a doubt the worst video game I've ever played and I will never defend the game in any possible situation ever.