While the overworld is overly large (especially with a virtually useless map) and the transport points are placed poorly, Mega Man ZX injects something fresh into the Zero-style formula without straying out of Mega Man territory. The biometal transformation mechanic is done well for a first attempt, though Models F and P often left something to be desired, what with F's inability to move while firing and P's general mediocrity. Each boss is unique and memorable, with easy-to-learn, hard-to-master patterns and character to the bosses themselves. The stages never seem overly long, though a select few fall victim to poor design choices (I'm looking at you, Area K). The story often grounds itself in the Zero series, but it introduces several new concepts, characters, and locations that keep the player wanting more of the world of 24XX. When it comes to fully completing the game, the hidden disks, while a nice bonus for players who want a deeper look into the world, don't give any rewards as a result of collecting all of them. I personally enjoyed the little blurbs about each enemy, but on the whole it isn't worth it. The Life Ups are fairly easy to find without requiring too much of the player. The sub tanks, on the other hand, are an entirely different story. Two can be acquired through very simple means. Of the other two, one requires a needlessly hard trek through a lava-filled area, and the other requires repeating two separate sidequests on three different occasions. And although the side-stories presented in the optional quests build the world in an endearing way, the energy crystals earned from most of them never really made me want to do all of them. Virtually each and every NPC is unique in design and personality, and it was a lot of fun to just talk to them and hear what they had to say, even if they added nothing to the story on the whole. Where the game really excels is the gameplay. It's fast-paced, gradually raises the difficulty, and challenges you to think around problems with the biometal system. Combat flows easily, especially with the saber-centered styles of Models Z and H. If you're looking for an addition to the Zero series' solid gameplay and story, this is the game for you. If you've come straight out of the X series, you might want to give this a pass. Mega Man ZX gets 4 stars out of 5.