ciV is a classic turn-based strategy. An open-source port of Civ V.
Extremely tactical and interesting! The game is very light and has no advertising, which makes the gameplay very fluid and immersive. It is not very intuitive and it may take you a while to understand what is happening and/or the relevance of each feature, but if you don't mind trying to figure things out on your own and you like strategy and thematic, go to front!
All the tutorial information is available in-game at menu > civilopedia > tutorials
Credits to Yair Morgenstern