Developer SquarePlay Games' promising underground station management sim, Overcrowd - a game I've had my eye on for a while - is now available in Steam early access.
Overcrowd: A Commute 'Em Up, as it's more formally known, tasks players with constructing and successfully running an underground transportation network, one station at a time, in the almost-but-not-quite-London city of Lubdon Town. In early access, three modes are available: there's a free-play sandbox mode, a challenge mode, and a campaign, unfolding across five procedurally generated levels.
In the campaign, the goal is to work through all five of these increasingly difficult maps, with procedural generation affecting things like the position of immovable concourse tiles, the location of tracks (which are fixed to connect to the broader network), and environmental elements that you're forced to build around. By cultivating a successful station, you're able to progress to the next, and can even hop between existing maps to improve network efficiency.