For a reimplementation of Civ 5, I would recommend you to take a glance at Unciv (https://github.com/yairm210/Unciv). The development is quite active. It's made for Android, but runnable using Java in the terminal.
I can recommend https://www.widelands.org/
Don't ask me how many hours I wasted with that, just to experience the wuselfactor. The mission is also quite fun.
Another good timewaster is https://7kfans.com/
But you'll probably only enjoy it if you played the original in your youth.
I've been playing a remake of the classic RTS Total Annihilation. LAN games with the entire family. https://www.beyondallreason.info/
Based on a open source engine, the devs have been busy remaking things to use all original assets and improving the interface. The game it self is based on another open source project called Balanced Annihilation that aimed to make TA a much more competitive game while preserving the original feel.
