It’s a cross-genre strategy/rpg with an interesting story and great gameplay. The gameplay is reminiscent of “Battle for Westnoth” with a bigger emphasis on role-play elements (Skills your characters gain, different equipment you can shop/loot) and the story. No silly stuff you purchase with real money here, or in-game adds.
It’s the third game of the series, after Swords & Earrings and Knighturn. All of them are great but Kingturn is probably the most polished one so far. I think Rpgwatch should consider covering it.
There is a “light” version that you may download for free but the full version is well worth it with over 60 scenarios.