This is the type of debut I live for.
The book is so immersive in its world, characters, and magic system. The world was extremely well done (although maps weren't in the ARC, I know they are in the finished copy, but I was still able to picture things without a map and that's a plus!). I felt that the author did an amazing job with the history of the world. It has the type of mythology that sucks you in and makes you think that this could be real. I also just think the different types of races were superb - reminded me a bit of Lord of the Rings in that dynamic. The magic system was also interesting - unique for each different race, which gave the story a whole new complexity.
The only thing that I would "gripe" about (and it's not really a gripe that bothered me, just a point I'd make) is that there were two individuals introduced that could have conceivably been a love interest. The first introduced had great chemistry with the main character - which serves a purpose. The second character also has different chemistry with the main character, but I always wanted something more to happen with the first character. This may be the first book I could say that I might not have minded a love triangle because I think this author could have pulled it off! Sadly I did not get my wish (yet, there's a sequel coming!), but overall I think the relationship in the book was well done! It's also relatively slow-paced - several months do occur from the time met to the time they "get together" but it didn't always seem like that because the time wasn't shown on the page (i.e. you would be told several weeks or months went by instead of seeing it unfold, which means that the romance seemed to be faster than it actually was).
Overall, I think this was an excellent debut full of magic and rival heirs and romance that is setting up for a wonderful series!