Grew up playing Wesnoth, still adore the game. There is a TON of third party content and a serious extended universe, too!

An absolute gem I came across randomly many years ago. Picked up Mewgenics and it left me wishing it had some mechanics from Wesnoth like faster animations (Mewgenics caps at 4x), undo action (at least if the action doesn't trigger any rng/damage behavior), skip enemy turns.

I only wish they added more campaigns into the official lore.

I love this game. It is also fairly easy to tinker with the units if you are like me, that is a big win.