It was an enjoyable, easy read, a well thought out story, and I will definitely move on to the next book if/when it comes out. Overall, I would rate it 4 stars.
If you like stories similar to Beneath The Dragon Eye Moons (by Selkie Myth), Vainqueur The Dragon (by Maxime J. Durand), and/or Themis Files (by Sylvain Neuvel), you would probably like Dead Tired.
Be warned, there are very minor spoilers ahead.
The story starts when Harold, a character who loves to learn and research, wakes up from his extraordinarily long nap. He is very powerful and doesn't really face any physical challenges. Instead, the story focuses on the narrative and uncovering what happened while Harold was asleep, and sprinkled in with Harold's magic lessons to his limpet, a girl who has a similar inquisitive mind but is a bit preoccupied with a desire for revenge (the narrative doesn't focus on it though, and will probably be something important in a future book). The magic is based on science, and as someone studying astrophysics in college, the author seems to be pretty informed, and it gets my stamp of approval.
The author, Ravens Dagger, seems to have learned quite a bit from his previous stories, and Dead Tired shows his growing expertise. One of the issues I have had with his previous stories is that the pacing feels off, but with Dead Tired, I feel that Ravens Dagger has found a pretty good pacing. And the narrative itself, which explores the world and how it compares to its past, is pretty interesting. Also, one of the big questions in the book is why people aren't able to access the system anymore. In between the world-building is some humor (there are quite a few puns) mixed in with some pretty good character development.
I would say Harold resonated with me quite well in that he is a researcher, and so am I. The humor was fun, and the world-building and pacing were excellent. The narrative is well-developed. It's a pretty easy and fun read; it did make me think about a few things, and the story was well thought out, but there also wasn't anything super deep. Overall, I would rate it 4 stars.