Volume 2 of Hero 6th covers everything that doesn't involve chargen.
The Hero combat system is both complex, flexible and fun. It provides the flexibility during combat to make all sorts of attacks, rather than the standard "I hit."
It has one of the best hit location systems I've ever encountered, including the very innovative "high shot" and "low shot" that provides easier hit modifier penalties.
One of my favorite things about Hero is the initiative system. Characters with a higher speed get more actions in a turn, which makes more sense than the standard init system most games have.
The adventuring section covers nearly every possible situation the PCs will encounter. And the book is very well-organized, so finding the rule you need on the fly doesn't take a lot of time.