I liked it and I'm excited for the next book.

I gave it 3 stars, because I find myself disappointed with Brandon Sanderson's "alien dimensions". It's the same as in Stormlight Archive. There is a mysterious alien dimension! (The Nowhere here, Shadesmar in Stormlight Archive.) It serves as the basis of all magic! Mystical creatures dwell there! Ancient portals let our heroes eventually enter the alien dimension!

It all sounds so exciting and in both cases I was so hyped! And when we see the alien dimensions they are kind of interesting. I'm kind of happy with them. But what happens there is surprisingly boring. They travel a lot? They meet mystical creatures and those just help/hinder their travels in mundane ways. They entered these fantastic alien worlds, and just do the exact same stuff as they do on any other weekday. To make things worse, what they do in the alien dimension is to a degree detached from the real world. Spensa even laments this a lot.

Plus the Path of Ancients is a massive infodump. It helps break up the boredom of traveling, but there's not a lot of drama you can build on travels and infodumps. For characters we only have Spensa, M-Bot and a new cast. Just like in Starsight. I think the new cast was great in Starsight. But I didn't find it memorable in Cytonic. Chet is a cartoon character. Peg's character is hard to follow. She becomes best friends with Spensa after she wrecks her knee because she's a good pilot? The new alien species are flat. A humanoid with big teeth that plants a tree. A birdman. And some crystals. Only the crystals are functionally different from humans, and they can't do anything.

With all those complaints, the book still does its job for worldbuilding. Maybe we just have to chalk this one up as one huge infodump. We learn everything about the history and mysterious workings of this universe. I'm on board with all that, it's a cool universe!