Stronghold Crusader had the best gameplay in the entire series, but the graphics were getting a little bit outdated after a decade. This HD re-release makes it look good enough to last another decade. Don't expect fancy 3D graphics, this is old-school isometric 2.5D.
The gameplay is solid. There are tutorials to teach you the basics and there are two "crusader trails" with about 50 missions each to give you a lot of different scenarios to play through. There are also campaigns with a story to them.
You play as a lord in the time of the crusades. You start with a small manor and a hand full of troops and there are enemies who want you dead. Build farms to grow food to keep your population alive. Gather resources such as wood, stone and metal. Build up a castle wall-by-wall according to your own design. Put down towers of different shapes and sizes: small tall towers to give your archers extra range, and big lower towers on which you can mount siege weapons. Have your population craft weapons to train soldiers or hire mercenaries with gold. Then try to invade your enemies' castles. Build catapults to destroy their walls, or use siege ladders to get your archers on their walls to turn their safe castle into a slaughterhouse. Beware of hidden traps like spike pits and burning oil.
Skirmish mode allows you to pick from a few dozen maps, some balanced and some unbalanced. Want to play 4 vs 4 on a balanced map? Want a real challenge, then pick an unbalanced map and stack the odds against you.
The AI does not have traditional difficulty levels, but there are a number of AI personalities that have their own strategy. Fighting against the Caliph means you have to be prepared dirty tricks like waves of slaves trying to burn down your farms, and fire arrow archers trying to set the ground on fire when you try to take his castle. King Richard attacks with honor and superior force using siege weapons and heavily armored units. The Sultan is a dreamer who focuses more on building an economy than training a superior army. The Snake thows large numbers of archers and spearmen at you, favoring quantity over quality.