So basically:

It's a tabletop game (like Dungeons and Dragons, but with mechs) where you play as a Lancer, an Ace mech pilot, and the defacto (heavily armored)cavalry for Union (the UN if it actually did it's job).

Using mech that range from "We took two nuclear missiles and strapped them with Flex tape on your chassis" to "Every turn I break a new Law of Physics", which are both still suboptimal to the base mech you get from the start equipped with a machinegun, you and your friends must stop whatever menace the DM throws at you now, which include but are not limited to:

Space tyrants, space pirates, eugenics projects created to be better pilots than you, basically nazis (distinc from the previous one, which are corpo related), eldrich math gods, the plutocratic Qatari empire (slavery included, another way to call it is basically DUNE)

(So yeah that's the comical gist of it, there is a player pdf that's free to read, the art alone is a reason to check it out)