Okay, here is the thing: It improves upon Tiny Dungeon, but at the same time it is a hot mess.
-It has variable difficulty for tests, which you can easily implement in Tiny Dungeon too.
-The layout and artwork is surprisingly good
-There is lots of races or "heritages" to choose from (24!)
-It delivers what it promises- it is twice as complex as Tiny Dungeon, with variable damage and armor rules, too.
-it has better fleshed out advancement rules, so you can play a campaign with a sense of real advancement
-some of the traits are not thought through (for example, the Berserker Trait lets you roll with one less die in combat to get +1 damage for each success.... which makes no sense really, because light weapons do 1 damage for each success, and heavy weapons do 2 damage for each success. So the only circumstance this trait could be beneficial, if you roll with 2d6 and get two successes, and you get +1 damage. Nope, not good at all)
-I am not fan of the AC system. A damage reduction variant would be much better. (Right now armor makes you harder to hit, and does not prevent damage... So, by wearing armor you become a ninja. Yes, it is the same in D&D but I simply hate this)
-The monsters are not fleshed out enough. Their trait list often points to other pages. (i.e.: Berserker: As per the fighter Trait). Come on! Most traits are only one sentence! Why do I have to flip the pages looking for this trait? Just copy paste it. Also, some monster are missing obvious traits (i.e.: the Troll have a reach of 15 feet, but Giants doesnt have any?)
-In combat you can do "special effect actions", some of which are odd. Okay, you can stun, stagger, knock down... and then there is root and weaken. Well, how do you do that as a fighter? Mechanically they are OK, but description-wise I dont know.
To summarise: It is not a bad system. Basically, it is now almost the same complexity as D&D 5th edition. I just hope that gallant Knight Games clear up or rewrite some of the traits to make them balanced. There are lots of good ideas in this book, and if this was my first RPG i would have been content. But right now I just feel it need to be a little more perfected.