Very in depth turn based strategy. The core concepts of building and specializing your cities (commanderies) will be familiar to Civ 4/5 players after about 10 - 15 hours, after which you'll probably want to restart from making so many early errors.
Steep learning curve, immensely immersive, character management can take quite a bit of time towards the late game, but it's all about how much you want to optimize vs. hitting that next turn button. You'll be fine if you don't agonize in the details of character gear and talents, but it can be a definitive factor in how your faction runs.
Overall, I'd rate this higher than Civ 4 or 5 for those willing to invest the time to learn. The largw number of starting campaign situations(leaders) can provide hundreds of hours of different playstyles and diplomatic scenarios.
Recommend a more modern GPU to render the large scale army battles (which there will be many). The level of detail of watching units collide at close up, launch fire arrows or treb. shots, is amazing and worth the effort of learning this game.
Final edit. If you care about "finishing" a campaign, consider it will take you a hundred hours to do if you take your time with your decision making. Not exaggerating.