The sibling to Mighty Monsters, of which a good 50% of the text is copy/pasted from one to the other. To copypaste a part of my own review: "A modification of the rules typically used with Ganesha games, upsizing a unit to be multiple parts and having a lifebar that makes things riskier for the monster the more damage it has. With the emphasis being on body parts, the creation of a monster is very flexible and grants plenty of variety. They have been kind enough to include lots of archtypes implemented to create most of the classic giant monsters." Replace "monster" with "giant robot" and you'll get most of the gist.

The biggest key difference here is that mechas take damage differently, suffering more immediate effects and risking their pilot being knocked out. That said, there's plenty of bits and pieces tailored specifically to the mecha genre to give this its own feel from its sibling book.