EDIT: whoops, i misread this as the worst game you played in 2018 but I already posted, so here you go: I don't generally make a habit of playing bad games, but this year I sat down and played through Bubsy: The Woolies Strike Back on my PS4. I kind of sort of like the SNES ones in a nostalgia drunk sort of way (every game is great when you play them at 6-years-old!), so I was curious and I got it for like 11 bucks.
Here's the thing: it's not a bad game really, but it is an extremely boring game. It's entirely playable. The levels though, are basically just straight lines completely covered in collectable yarnballs. You can run from beginning to end fairly easily with little obstacle, in every single level in the game, in the span of like 1 to 2 minutes. As a result, you can easily beat the game in like 45 minutes. BUT there's a big caveat to this game's fine-ness. The bosses. The bosses in this game suuuccck. Bosses with extremely monotonous and long attacking phases with a limited moment of vulnerability at the end. At the end of the game these phases can last minutes before you get a very limited window to hit the boss one time. And if you miss the window, which you often easily can, you have to wait for it to cycle again. It took me damn near 15 minutes to beat the final boss, and it was an entirely boring 15-minutes too.
4-5ish out of 10 on that one from me.