To be honest, I don't truly hate a game to the bottom of my soul, every game has strengths and weaknesses, positives and negatives etc.
If I had to say the game I least enjoyed, it would have to be 'Shrek's Treasure Hunt' for the PS1. It was a dull item collecting game and I remember disliking it due to its repetitive structure which just involved collecting indiscriminate objects that had nothing to do with Shrek. I'm just going from memories though, it has been a long time since I have ventured down that dark tunnel of movie spin off games.
Seriously don't buy it, I was obviously a silly 6/7(/8?!) year old to think it had merit enough for my saved up british pounds.
I was also looking through the collection and I found my mom had bought 'Barbie Race And Ride' for £20! Big mistake is all I can say.