Alternate universe and time travel? Okay, sign me up! Because why not? 
 I love love the premise of this book though I'm not usually a time travel reader but I love the idea of it - a lot of crazy adventures. So, the whole concept of the story is about the Traveler and the Dreamer. The traveler can move into different realities with just a mirror - that is their portal and the dreamer is in charge of keeping track of all the possibilities and they are also the one whose assigning jobs for the traveler. It's like in the game, the traveler is the player and the coach is the dreamer. There is magical everytime that they switch different realities especially my one's favorite is when they went to the Victorian Era. If you're into Alternate Universe, I bet you should try this one. 
 The characters are so plain like I wasn't emotionally invested in them (because in every book it should have an emotional investment to get into them) but I don't have it. Jessa - she loves to write, a loving sister/daughter, and supportive bestfriend but sometimes she's a whiny. I don't have problem on it because I get it why she is whiny however there's no reason how her character stands out even the other characters like Ben and Finn. While, the love interest in the story is lacking some flame I wish there's no love interest here because it is much GREATER if instead of love triangle between Ben-Jessa-Finn, there are all bestfriends. I think the author is trying too hard to have a romance here but it is not working. It clashed to one another. The character development is shallow, slow, and bland. End of discussion. 
 On the contrary, I think this is a great introduction for the story and to the next book (I don't know if it will be a duology or a series). Even though, I don't like how the characters are, still, the whole concept of it are superb and I honestly can't wait to read the next book because who knows what will happen right? Sometimes first book in the series/duology can be a not-so-good but ended up with a lot of twists to the next book.