While there are definitely more objectively worse games like Heavy Rain and Sonic 06, I just want to say a bit on a more personal note that Final Fantasy XIII-2 was an absolute, unmitigated disaster from start to finish.
The story was pretentious, cringe drivel that made this sort of bizarre whiplash between being so absurd that it tackled its ideas with a comical shrug (the timeline split was being caused by a tomato fart) or smack it and smear it all across the player's face with all the subtlety with five bulldozers of varying size (Lightning is dead but gone but also not really but still but dead but gone but also not really) and it's all spearheaded by Noel Kreiss, a protagonist so poorly written that he was rejected from Kingdom Hearts. Just.. wow.
The battle system is a distilled array of confusing system after confusing system after confusing system with some monster-catching here and some spells there and a QTE or five too much, and the game does such a poor job with easing the player into its mechanics that I watch it all play out with glossed eyes and if I died, I had to force myself to pick up the controller again with all the determination of wanting to do homework, dishes, late-night hours and a few days of watching paint dry, simultaneously. The time travel aspect of it was a tad cool, so a tiny, teensy shred of redeeming factor is being found with the novelty of revisiting an area when you've changed the past to make it look different. But at that point in the game, I was so over it that I wanted nothing more than to pick up the game disc, tear it in half with my bare hands and use it in a game of frisbee only to realize that that incentive was being rendered moot by me having ripped the game disc in half.
And last but not least, the music. Oh my god the music. When that rapper in the battle theme goes "yo, yo, looking for paradoxes" I felt like a part of me just dissolved into the night in a million, tiny pieces of pure pain.