Read this back when I was 12-13 (19 now). I look back fondly. The best way I can describe it is as more of a cool and inventive fantasy novel with a Minecraft setting than an "unnofficial Minecraft-fan adventure." It's probably one of my favourite book series' that I've read, strictly for its creativity in using an otherwise "childish" setting to create something unique that can cater to both fans of Minecraft and fans of teenage fantasy novels. If that sounds like you, by all means pick it up and give it a read.