Space trading sims (such as the Elite series) have two very common weak points: 1. 3D flight simulation is a game-design nightmare unto itself, which not everyone enjoys playing even at the best of times 2. a crutching reliance on randomness and procedural generaton, making the universe shallow and exploration feel pointless. This game follows—as does its “cousin” project Naev, which is also free—closely in the footsteps of the Escape Velocity (1996) series by making two simple changes to the Elite formula: 1. replace the 3D simulation with an Asteroids-style 2D map 2. bring the randomness to a minimum: each planet—there must be hundreds—is placed by hand and has a little bit of lore of its own. The result is a very accessible and very addictive trading-and-questing game, with arcade-like combat, plenty to see and explore, and plenty of freedom to set your own goals, but plenty of hand-written, branching plotlines and subplots too.
This game is a clone of the post-2008 ("3D") version of the Dwarf Fortress base-building survival game, with an improved interface, simplified mechanics, and a science-fiction setting. Although just one of many such clones, it seems to have been made with uncommon skill and care, successfully distilling the DF formula down to, I think, the simple core mechanics that make it fun for the player (including losing!) , while also, through the graphical interface, making itself available to a vastly expanded base of such players. You might say that RW is to DF as Project Zomboid is to Cataclysm:DDA. Would be 5 out of 5 stars if they did the honest thing and released it as freeware.