Note: It's currently in Early Access.
The game added Linux support last month, although I don't imagine it was too difficult since it can be run in a browser as well. Don't let that instantly put you off though. I wouldn't let it being free put you off either, as the developer is very clear about it not being pay to win.
First up, check out their trailer:
Here's how they officially describe it:
Road Dogs is an MMORPG in the privateer/trader genre, and a reincarnation of Steve Jackson’s Car Wars — a 1980s board game in a hybrid with the global mode of Mount & Blade and Fallout. Imagine how a classic MMORPG would look on an old arcade machine — Road Dogs is our fantasy in this theme. Our goal is to create a live PVP-world, something like 2D EVE Online, using the trends of recent years as elements of .io-games, and their minimalism, arcade similarity in particular.
Annoyingly, they don't have Steam integration quite done yet. So when you pick a server, an extra window will pop up asking you to sign in with Steam. I imagine that alone will put a few people off and rightly so, it's not a good look for a game, but hopefully they will get proper Steam integration setup as it's further developed. Thankfully, you do only have to do that once.
It's a vehicle-based MMO, so rather than controlling a single character with hunger and thirst, you travel around in customizable vehicles. What makes it different, is that it's not in 3D, it uses a very retro-looking radar-like interface for when you're on the world map:
You can zoom out really quite far as well, to see even more:
It certainly is quite stylish, with the retro-future style to it. I haven't had any trouble navigating with it being quite clear, so it's quite welcoming for new players. It offers up a tutorial too, which does at least give you a helping hand for a few minutes at the start.
Travelling around is real-time and since it's an MMO, you could pass by other players on the map. Surprisingly, I've actually seen a few random players driving around and it's actually pretty sweet when you get a bit further in, especially when you see combat and you floor-it to get away, or join in and hopefully not lose your first set of wheels.
It's also quite a slow game, especially at the start when you've got the most basic vehicle it can take a while to get anywhere. For those who like to chill out, travel across the wasteland, trade and do whatever it might be a nice MMO for you, certainly different to the usual sorts. I've done a few quests, purchased a few parts to upgrade my little Beetle and it's been an strange ride.