What Euro Truck Simulator is
Euro Truck Simulator is the original truck simulation set in Europe, and it's the game that started the genre. You drive European long-haul trucks and move freight between cities like London, Rome, Berlin, Madrid and Prague, plus plenty of others. The point is the driving itself: pick up a variety of cargoes and get them delivered on time. The trucks are modelled in detail after real vehicles, and the cabin instruments actually work — flashing indicators, temperature and low fuel warning lights, wipers, and a full set of gauges. You can pan the camera around the cabin as if you were sitting at the wheel. The game covers the tags you'd expect from this kind of sim: driving, relaxing, open world, exploration, management, sandbox and atmospheric, with both first-person and third-person views.
Playing it with friends
The Steam feature listed for this game is Remote Play Together, which is how your group can share it. One person owns and runs the game, and the others join in over the stream. It suits a laid-back session: someone takes the wheel, the rest of the group rides along, watches the route, and keeps an eye on the gauges and the cargo clock. Because the whole appeal is steady long-haul driving rather than fast action, it works as a game you can put on while the group chats. The tags also list online co-op and multiplayer, so check the store page for what's actually supported before you plan a session around it.
Before you start
The driving is meant to feel faithful to real European roads, so expect a slower, more deliberate pace than an arcade racer. Deliveries are timed, so the pressure comes from traffic, fuel and keeping the truck in one piece rather than from speed. The game is moddable, but there's one important caveat: unofficial mods are not supported by the Mac OS version, and those file formats are not compatible with the Windows PC version. If your group mixes Mac and Windows machines, sort that out first so nobody ends up with a mod setup that won't load.