What's the worst game you've ever played, and what was so bad about it? For me, it's the following...

I got a Gameboy Advance back in the early 2000s and I picked up Super Mario Advance, Pokemon Silver...and this.
I was young, and I didn't know any better...but I learned quickly that a game tie-in is almost always a red warning flag.
Firstly, the theme music. Here's a Youtube "lets play" of the game:
https://www.youtube.com/watch?v=O0J8LdyJsDU
Just listen to that music. It's the audio equivalent of rubbing your eyes after cooking with chillis. The word "grating" doesn't do it justice.
But hey, it's the Gameboy. A lot of games were like that on the system.
"Maybe it plays well?" thought my stupid young mind.
...go back to the Youtube video. Look at Bart's catapult. It's impossible to kill an enemy unless they're at a very precise angle - which makes things pretty damn difficult as most villains are mobile, and need to be shot more than once to die.
The gaming is VERY repetitive. Go through a door, grab a key. Go through a door, grab a key. Go through a door...you get the picture.
It's also very, very difficult not to get hit. If you bother to play as far as the boss levels (again, I can't emphasize enough - YOUNG AND STUPID!) you'll sometimes find yourself in a situation where you're killed by one hit, and those hits are impossible to avoid. And when you do get hit (it will happen) you're right back to the start of the god-awful level.
One of my biggest regrets is buying this game...
So, over to you - what's the worst game you've ever played? (No need to be as long-winded as me!)