Build your own model railroad world
Train Frontier Classic is a sandbox about laying out a landscape and running trains on it, in the spirit of a model train set. You sculpt the terrain, thread miles of scale track across it, and drop in hundreds of props to dress the scene. Track building is loose enough to go wild with, including roller coaster style layouts, so you can make a tidy countryside line or something that loops and dives. You also set up your own train, choosing from dozens of train cars and engines to run on the track you built. It's a casual building game first: there's no fixed goal, just the scene you decide to make.
Ride it with your friends
The building side and the riding side connect through multiplayer. Once a map is finished, you can go online and share it, so other people can load it up and take a ride through what you made. In the other direction, you can join someone else's world and run, drive, and build alongside them. The world builder is designed to be quick and easy, which matters when a group wants to spend the session riding rather than editing. Derailment crashes and explosive effects are part of the sandbox, so trains coming off the rails is a normal outcome rather than a failure state.
Before you start
Train Frontier Classic is in Early Access, so expect the game to still be changing over time. It's built to run on a wide range of system specs and is aimed at all ages, which makes it a reasonable pick for a mixed group. The tag list covers both singleplayer and multiplayer play, so you can work on a map on your own and bring friends in later. The game is a 3D sandbox with no prescribed objective, so the session runs on whatever the group feels like building or riding that night.