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.
I don’t want to sound cliche but yeah. E.T.
And there are people saying that they immediately knew it was bad. Not me. I played it for a stupid long time. When I was 12 I would play any video game for as long as I could. And I remember screen after screen of just terrible, unimaginative redundant gameplay and wondering if I was doing it wrong…