Details and spoilers below the cut.
Things I adored about this movie:
* The villain is an oil company and most of its employees. \o/ Bonus points for NOT doing the usual mad science villainy.
* The scientist is actually one of the more complex and interesting villains. He starts out as a company man, and there is quite a litany of disreputable things he has done: lying, cheating, falsifying reports, etc. But he won't commit murder, and when it becomes clear that the creatures are sapient, he helps them escape. I really liked that ethical discussion, especially in light of all the recent entertainment where there's basically no distinction between the good guys and the bad guys.
* This also highlights the dangerous situation of a company town. When there's only one major employer, heinous things tend to happen, because it's like not being able to afford leaving an abusive spouse no matter how much damage they do. This is a very real problem and it was handled thoughtfully.
* Another aspect of small-town, highschool life is the sociodynamics. There are several scenes highlighting Trip's place toward the bottom, but not actually at the bottom, of the pecking order and how he relates to others both above and below him. One subtle point is that the popular boy's girlfriend actually pays attention to Trip and helps him in discreet ways. A moment of breathtaking fanservice is that when there's a need for extra trucks, the popular boy's truck gets repossessed and hauled off to become alien locomotion.
* Two of the human characters show distinctly different intelligences, in ways that influence the plot. Trip has mechanical intelligence and little interest in school. He's good enough to rebuild a truck into a piece of adaptive equipment for an alien overnight. Meredith has naturalistic intelligence with a keen interest in academics. This comes up in a discussion of her plans for escaping the nowhere town they live in, which is typical of teens in nowhere towns. The interesting part happens when they're talking about how Trip modified the truck, and he kicks into technical terms, and she stares and him and says, "You're not dumb!" Because up to that point, she had only seen him in contexts where his intelligence was hidden. Also noteworthy: the romance between them is kept light and mostly blown off instead of doing the usual love plot. Which makes Trip the only teen hero I can readily recall who isn't thinking with his dick.
* The creatures aren't extraterrestrials, but subterran. I haven't seen a good under-Earth movie in ages. In this case, the creatures live in a network of underground vents and caverns filled with a mix of water and air. They eat oil. The company broke into their home while drilling, and they got sucked up the pipes.
* Aside from handwaving a few things (like the fact that creatures living at high-pressure depths tend to liquefy if brought to the surface) much of the science was surprisingly good and full of eastereggs. There are deepwater ecosystems not reliant on the sun; they do have bioluminescent life. Oil is a rich source of energy and a few lifeforms can digest it. Cephalopods are very smart and understand torque well enough to open a jar. In fact if you give a canned treat to an octopus who already knows that trick, another octopus can learn it by watching the first one open the jar. They can crawl on land somewhat and can fit through incredibly small cracks. The "Simon" game scene is based on an actual study involving dolphin communication and cooperation in which only one dolphin knew the answer that would deliver a treat and communicated it to another dolphin. I have to wonder if there are as many eastereggs for the truck stuff as for the science stuff -- I spotted a few obvious ones like trucks crawling or jumping over things, but likely there are more.
* This movie's grasp of disability issues approaches the quality of Mad Max: Fury Road. One of the supporting characters is a black man in a wheelchair. It's not shiny, but it's incredibly appropriate -- it has almost no back and thus no push handles, the wheels are canted for stability, and the frame looks like it was handmade out of heavy pipe. Since that guy works in a junkyard, it's entirely possible he either built it himself or modified it. This is a huge improvement over usual portrayals of wheelchairs in the media, although sadly I couldn't find the article I once read that explained why most such portrayals are terrible. Neither is the wheelchair ostentatious. Nobody ever makes a big deal of it; he just goes around doing his job. In fact there's a totally awesome blue-plate heroic moment at the end of the movie where he's hitching up a broken-down car to tow into the shop. Because tow truck drivers are heroes. :D
The creatures don't have skeletons and aren't used to gravity, so they can barely move on land. However, Creech quickly figures out that he can move on wheels. Going from the early part of the movie to the later parts, there's a clear progression as he learns what he can do and navigates in more efficient ways. It doesn't take long before he is traveling with a great deal of speed and agility. Now, I recognized the truck as adaptive equipment right away, because I'm used to thinking about how to accommodate lifeforms across different atmospheres. I was amazed when Meredith came right out and said, "The truck is like a wheelchair for him!" Whereupon Trip said, "No, he's like an engine for my truck." Each of them described a new situation based on things they already knew. And so help me, that whole handful of characters proceeded to play out the argument over whose body this was and who the equipment belonged to and thus who was in charge, perfectly intelligibly, even though only the human characters were doing it in English. The articulation of the trucks is brilliant, too -- they're not just rolling, they can jump and climb. We're watching aliens do parkour in truck suits.
So technically, that's four characters with disabilities, and one of them is a main character. The human one is disabled in everyday life, but it doesn't seem to slow him down much. The other three are disabled in context, and that isn't handwaved -- they're quite vulnerable, although not completely helpless, on land without wheels. Both the limitations and the solutions are shown honestly. And then there are some lovely scenes showing the creatures in their native environment, where they are not disabled but are beautiful and graceful. This makes it possible to contrast different ways of handling disability, AND avoids the trope of undoing disabilities because the black dude is still out heroing in his wheelchair (alive! which kills another trope) at the end of the movie. \o/
* Another surprising plot twist involved family dynamics. Like many heroes, and an increasing number of people in general, Trip comes from a broken home. The setup shows his mother's boyfriend in a negative light at first. But when Trip really needs help, his birth father betrays him, and it's the boyfriend who risks his life to help. There's another tail scene at the end of the movie when the two of them are working on a truck together. It's a wonderful pointer about how fatherhood isn't about having a timely orgasm, it's spending time with your kid. Or someone else's kid that you picked up along the way.
* Meredith's horse is almost bombproof. There's one instance of rearing in response to a loud noise, but no freaking out over the creature in the truck. In fact they go barrel racing through Meredith's wilderness obstacle course together.
* The level of violence is typical of a classic teen adventure flick, rather than today's "kill everything that moves" approach. There are plenty of fistfights, occasional shooting, lots of chase scenes and destruction of property. But nobody seems to get killed, and the company fucks who are trying to commit murder and genocide are not successful. Roughly equal attention is paid to problems that can't be solved by hitting (i.e. how to feed and mobilize an aquatic species in a foreign environment) plus some subplots on social lines (education, escape from a dead-end town, father-son dynamics, etc.).
* The humor is exceptionally good. Much of it is lowbrow stuff but it's well done. There are a lot of sight gags with absolutely pitch-perfect timing.
Go give these people your money. Maybe they'll make more movies worth actually watching.