-
shapez.io
Discontinued shapez is an open source base building game on Steam inspired by factorio! [Moved to: https://github.com/tobspr-games/shapez.io] (by tobspr)
-
InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
You might like Shapez or Satisfactory or Dyson Sphere - but afaik none are nearly as complex as Factorio, especially if you include Factorio's modding community.
Probably not nearly as complex and a bit different, but: OpenTTD
NOTE:
The number of mentions on this list indicates mentions on common posts plus user suggested alternatives.
Hence, a higher number means a more popular project.