Only one serious issue here gets in the way of all the crusading fun--a crash bug that takes down your armies even more effectively than Richard or Saladin. GameSpot experienced a few abrupt crashes to the desktop in the deployment stage right before battles. These didn't happen often enough to warrant calling the game unstable, but they were enough of an annoyance to make everything seem a little bit rickety.
Even with this issue, however, Lionheart: Kings' Crusade is a smart RTS with a lot going for it. The tight focus on the battlefield and the RPG elements that force you to care about your troops really draw you into the action and keep you fighting.