For me, it has to be Alien: Colonial Marines as it’s terrible due to inconsistent frame rate (moments the game ran smooth and times where lag was insane, even with the best hardware). Both player & enemy AI is crap since the combat wasn’t even that immersive plus Xenomorph AI isn’t as intimidating due to it being poorly implemented.
It really was so bad. In that egregious way that just shits on your childhood. It came out during the rise of popularity of the animated Batman and Superman shows that were top notch productions and I remember being excited that it was a game and fortunately I got to play a demo at toys r us before I wasted money on it.
The one silver lining is watching humorous YouTubers do long plays of it now.