Kingdom Rush is a tower defense game where your goal is to block your enemies' path by placing a series of defensive towers in their way. Your goal is to stop them from reaching your base and destroying your kingdom.
To stop the hordes of orcs and goblins from following the paths and reaching your kingdom, you'll have a good assortment of defensive buildings available. Some buildings help you attack enemies from a distance with arrows, others let you use powerful magic spells, while others provide you with soldiers to further stop the enemies in their tracks.
As you complete missions in the main campaign, you can keep improving your towers by earning arrows that inflict more damage or soldiers with more health. In short, by improving your buildings, you'll have more of a chance at winning in the more difficult levels. Plus, even if the enemies manage to get past your defenses, you can always use powerful spells to call troops or throw fireballs.
Kingdom Rush is one of the best games of its kind - a real must-have for fans of the tower defense genre. It's one of those games that will keep you hooked for many, many hours. Best of all: it's completely free.