I’m a little late for my worst fantasy and science fiction of 2018. Still, a late warning is better than none at all. I’ve no doubt missed some of the sand, but I’ve done my best to look at every film that had a chance to get onto this list. And I’m not counting ultra-low budget films without a real release. These are films that had studio backing.
Note: If I was expanding this beyond F&SF, Mission Impossible: Fallout and Tomb Raider would take slots below, and MI: Fallout is arguably SF, but as more people than not wouldn’t count either of them, I left them off.
First, a few special awards for films that avoided this list:
Most Disappointing: Deadpool 2 (My Review)
Most Unnecessary: Solo: A Star Wars Story (My Review)
Greatest Artistic Drop in a Franchise: Incredibles 2
Now to the 10:

#10 – Cloverfield Paradox
Swiping from Event Horizon, 2010, Life, Alien, and many ‘80s SF films, it never decides what story it wants to tell, so fails to tell any. (Full Review)
#9 – Truth of Dare
It’s a patchwork of previous movies. There is not a single moment you won’t predict, even down the order of the deaths. (Full Review)
#8 – The Nun
Yet another film in The Conjuring franchise, there’s talent all over this production, but there’s no story. It’s just “some evil stuff happens” till it stops. (Full Review)
#7 – Halloween
Maybe it wouldn’t seem like such a sleazy cash-grab if the filmmakers had anything to say or if it hadn’t all been done before in an earlier Halloween film. (Full Review)

#6 – The Titan
A sci-fi story about surviving on Titan, except there’s only 20 seconds on Titan. 50% of the film is spent in a pleasant glass house, and the rest at what I assume was a local Spanish YMCA. (Full Review)
#5 – Batman Ninja
This is what you show someone if you want them to hate Batman, comics, superheroes, and anime. (Full Review)
#4 – Puppet Master: The Littlest Reich
Shouldn’t a Nazi puppet film be fun? The murders are mean spirited, which kills the comedy. The silly moments kill the horror. And everything kills the message. (Full Review)
#3 – Slender Man
There’s no scares, no emotional beats, and no clever plot moments—there’s hardly a plot at all. It isn’t even memorable enough to rate as truly awful. (Full Review)
#2 – A Wrinkle in Time
An ugly After School Special with all the charm ripped away, it’s dull, simplistic, and an insult to children (Full Review)
#1 – Ready Player One
It’s a toxic stew of everything that’s wrong with fandom. It’s an obnoxious, sexist, racist rant in favor of nostalgia-fanboy mania, but it was made so poorly that the hate groups didn’t even realize it was for them till after its theatrical run. (Full Review)