Is Monster Trucks good? Hell no. Is it bad? It is a disaster. And because it is a disaster, it's almost kind of fun to watch. Presuming you don't go out and pay for it and have to find a theatre. Also, if you're an adult? Booze would help.
If I had watched Monster Trucks as a kid as a TV movie, I would not have hated it. It's pretty much exactly like Xenon or Smart House or any other one of a number of vaguely science-fiction-themed TV movies made for children. Monster Trucks' problem is that it's a movie released in actual theatres. And no one is, or should, go through all the effort of travelling to a theatre to see it.
Here's where I admit that I missed a little bit of the beginning of the movie -- thanks to the MTA for its tireless efforts in making sure of that -- and also say that I recommend that you, should you inexplicably choose to see this movie, should do the same. Because as far as I was concerned every single plot hole, and there were a ton, could have been explained in the minutes I missed. It fed a fantasy that the movie wasn't totally inept.
Monster Trucks is about Tripp (Lucas Till), who accidentally stumbles upon a monster named Creech (short for "creature") who, it turns out, can power his truck. Jane Levy plays his "love interest," Meredith. They find out that the reason the monster is with them is because it escaped the company that discovered it while drilling, and two more monsters are still being held captive by the company. Which plans to poison the all the monsters so that they can keep drilling. Because eeeeeeeevil.
The company is an oil company (of course), which ignores safety and environmental regulations (of course), and is run by Rob Lowe (...of course?) Lowe's got an accent in this movie. Not a Southern accent, as I think intended, but more like the accent of a British person trying, and failing, to sound American. His accent does not wander so much as appear from another dimension. It is a character in itself, and possibly the most well-rounded one.
Although Lowe is the villain, the "hero" Tripp is also a horrible person. I don't know why adults think kid characters have to be sociopaths, but here we are. Tripp uses Meredith for her father's money, uses Creech to drive the truck he can't afford to put an engine in, destroys the home of the father who abandoned and betrayed him, and is a dick to his mother's new boyfriend, who is the only good adult in the movie. At the end, Tripp uses another rich kid's love of him to steal two trucks and that kid is left holding the bag when the oil company's army comes looking for him. I think he might even kill some people. Tripp is awful.
Meredith is a quivering pile of neuroses that is forced by the script to say things like, "As a young animal rights activist, I have to ask." I don't actually blame her for being weird, since her dad never appears except by credit card. Both Tripp and Meredith are dressed as the 20-somethings they are and not the high schoolers they are supposed to be, adding another level of hilarity to this whole thing.
Monster Trucks wants to have a message. It tries out and discards scores of them during the movie. Accept new people into your family? Only after he kills a bunch of people for you! (Yeah, it's only after Tripp's stepdad straight up drives over a few oil company goons that Tripp likes him.) Don't judge a book by its cover? Meredith thinks Tripp is dumb, but he's not. He is, however, selfish and mean. Don't be cruel to animals... but do put them in your truck and make them drive you around. Environmentalism? Stop the company from putting poison down a hole by spraying it all over the surface instead. Surely that's not also an environmental disaster!
Oh, and the poison is bright neon green. Because it has to be or the kids won't get it. And the creatures? Are colour-coded by gender. Blue and pink.
The movie jumps from eye-rolling moment to mouth-gaping moment. I will grant it this: Thomas Lennon's always welcome as comic relief and he tries his damnedest to carry this movie. (He's an oil company scientist and Rob Lowe's lackey. His message: it's never too late to stand up for yourself, even if you used to break a ton of laws on behalf of an oil company. As a bonus, you will get off scot-free.)
If I had a bunch of friends, some alcohol, and the comfort of my own home to make fun of this movie, I could almost appreciate it. If I were a kid watching it at home after school, I could almost appreciate it. But dragging my arse to a theatre, during winter, when there are so many better movies I could choose to see there? No. Take your kid to Moana again instead.