"Dark Matter" by Blake Crouch feels like the book equivalent of a sure-shot, crowd-pleasing Marvel superhero movie. This isn't necessarily a bad thing mind you. The book is fast paced, action packed and entertaining. It falls under the category of "Science Fiction" - though I would say it is less "science" and more "fiction".
The premise of the book is based on the fairly well-known multiverse theory. So even though the science becomes outlandish after a while, the core of the story is good enough to pull it through. As for the characters, there is an underdog, easy-to-root-for protagonist, his love interest and a well defined crisp antagonist, completing the holy trinity that make a like-able story. And even with these basic ingredients, the book as a whole actually works ! It works as a perfect weekend read, it works as a perfectly adequate mindless thriller/action story, without getting too deep or philosophical.
Overall, a definite 4/5 from me. Fun and fast story without pretensions.