Unciv

An open remake of Civilization V for Android and desktop. Light, fast and fully playable offline.

Pro tips

1. Expand early: your first 3–4 cities set your pace. Favor rivers, coasts and resources.
2. Keep happiness at zero or above. Luxury resources are the cheapest source.
3. Pick one social policy branch and commit instead of spreading points.
4. Garrison every city, keep archers behind melee units and fight from hills.
5. Build a Library early for science before you chase wonders.

Image from the project's own page, README or Wikimedia Commons, owned by its creators. Source