Oh wow, was not expecting this, much appreciated!
You're not far off, it's based on Hnefatafl board game, which is basically medieval norse version of chess.
My first improvement is finish the AI to make it more challenging, right now the orcs are not trying to go for the king piece, so you could quickly find your way out and push for the corner.
Someone else's comment here made me think, additional enemy or friendly types with different moves or attacks is option, but I'd like to implement rogue-like approach with story mode maybe, there's a mission goal, and after beating each level, only surviving vikings will start next level, but enemies obviously will spawn in full force.
Original board game is also played on bigger 11x11 board, so that could add a little, I'd probably drop 64x64 pixel requirement for jam.
But it's all down to if I manage to implement my idea for AI, and if it makes game more challenging, and that will decide if I'll continue development on this one.