One of the most awesome online games ever. It's made by the guys who did Armored Core, but the game is very different. It's a much slower, tactical, group-based type of game; one might even say a "mech sim" if such a thing existed. You still build your own mechs (and believe me, you'll spend hours tinkering in the garage with your own designs) from parts you buy with money you earn from battles.
The single player is really an extended tutorial and is pretty much a throwaway after you learn how to play.
Online, however, Chromehounds rules. It's kind of like an MMO: there is a persistent war happening between three different national factions for control of the country the game takes place in. What this means is that the nature of the game changes even when you're not playing. You start by choosing a squad to join, and here's where it gets important: Chromehounds is not a game you can just buy and jump into online and play with anyone. It's certainly possible of course, but it's most rewarding if you can make some friends who play it first, or if you can convince some of your friends to get the game along with you so you can play together. Once you form your squad, then you choose a nation to belong to. There are three different ones (a U.S.A. clone, a Russia clone, and a Middle East clone). Each nation has access to different parts and specializes in different combat styles. Luckily you can change nations after the war has ended (about once every 2-3 weeks or so).
Once you have your squad, your nation, and your mech, you jump into any of the contested maps and play against either the CPU or another squad. Victory on a map earns you points towards your nation's control of that map, and once you control 100% of that map, you can advance the front of the war to the next map, with the ultimate goal being to reach and defeat a nation's capital home map to eliminate them from the war. Along the way you earn money to beef up your mech or create new designs. Once the war is over (either when one side wins or when the game's pre-determined time limit is up, usually a month or two), everything resets and you can start again.
If you're not into the online war, you can also play quick skirmishes against other teams for fun or to test your mech designs; these battles have no bearing on the outcome of the war.
Chromehounds is an awesome game, but having people to play with is the difference between being really bored and confused or having a really unique enjoyable experience.
If you know anybody who's going to start playing, drop me a PM and I'll join up with you guys. My old squad has been inactive for some time, but I'm always up to play Chromehounds.