I feel like comparing OTTD to OpenLoco is a bit similar to comparing Freeciv to Freecol. OTTD and Freeciv just had so much more popularity and development. But OpenLoco and Freecol are still nice to try.

Of course! TTD and Locomotion were developed by the same person. From my understanding Locomotion is closer to the Roller Coaster Tycoon engine and UI. Also I think I remember reading an interview in which Chris Sawyer said Locomotion had the cleanest code out of the three.

On that note, considering the original engines are similar I wonder if OpenRCT2 and OpenLoco have any big similarities in the code base as well…