The rule book is clear and well annotated. I enjoy the system as given. Would be a great way to introduce players to role playing for the first time. The sample adventures were unique, but lacked good situations for non-combat trait use.
There is a depth to skills that is character dependent, the more skilled you are, the more likely to roll under your characters target number - much like Gurps. Where there is an automatic fail in 5x5, fails which are not automatic (a roll of the same number on both D6) can be overcome with Karma - which is generated by rolling an automatic fail.
They then flip this for skills your character is grossly unskilled (or handicapped at), rolling a double is the only way to succeed and you get a karma for making it. "[Tr] Trouble: This is something that other people seem to be able to do without much difficulty. But not you. This always gives you trouble." This strikes me as a nice way to round out a character, a hydrophobic air-man character for example, really shouldn't be attempting to swim. A vegetarian might have Trouble eating meals with any meat in them.
I enjoy the combat system, it's got a depth to it that I find missing in many role playing systems which rely on attack vs AC or another relevant static number. "The Combat Traits are: Interrupt (act before the enemy,) Attack (successfully hit the enemy,) Defend (negate the attacks of an enemy,) and Resist (shake off the effects of damage to keep fighting.)" Armor only reduces the likely hood of critical damage. However characters are not massive wound tanks as depicted in some role playing games, in 5x5 combat is harmful and threatening. Despite the simplifications and low hit points, with some of the examples presented in the game the rules provide a good format for experimentation and customization. However the rules as stated are probably best used in tightly focused scenes with a limited number of opponents rather than large amalgamations of opponents.
The magic system was a bit of a disappointment, after having enjoyed the combat section so much. Some better examples or even two samples of combat magic would have been appreciated for scope and reference. If I used this system I would think long and hard about allowing magic, perhaps adapting a more familiar setting. Attaching target numbers to a short list of spells which are supported by a few general traits comes to mind.
One detail that was over looked.
Page 13. Task Rolls has a line regarding rolls for actions without
traits, which is clarified in the section Rolling Unskilled. However
this section does not exist, as written. It is covered on the top of
page 14 in the section All Other Tasks. But not with the exact
phrasing giving on page 13.