Kingdom Defense is the fourth Ball And Wall episode, in pixel art: 30 rounds in five places, from the forest through a goblin village, a swamp and the caves to a graveyard. An army of goblins and monsters marches down towards your palisade, a step every few seconds, but only while your cannon ball is flying. Beat every unit before it gets there: a unit that reaches the palisade burns it and you lose a life. The round is won when the army and its houses are gone.
Controls, the goal of the game, options and rankings are on How to play Ball And Wall.
A goblin gives 20 points, stronger units more (a troll 400, the minotaur 800), a gold stone 30 and a mushroom or a pebble 5. Units that a barrel or a bonus breaks count too.
Goblin: breaks with one hit; the army marches down a step every few seconds while a ball is in play.
Skeleton: takes two hits and turns red after the first; stronger units take more (a troll eight, the minotaur sixteen).
Goblin house: takes three hits and burns more after each; until then it sends a new goblin out of its door now and then.
Barrel of TNT: one hit and it blows up, breaking what stands round it; barrels next to it go off too.
Thrower: a gnome with a slingshot (and goblins with dynamite, sharks, gnolls, shamans) throws things at your paddle: dodge them.
Flyer: bumblebees, bats and imps fly from side to side while they march.
Gold: breaks with one hit, and a bonus may fall from it.
Mushroom: mushrooms, pebbles, bushes and bones break when the ball flies through them, without a bounce; the army tramples them.
Stone pillar: cannot be broken; a unit behind it waits.
Rune portal: a ball flying into it comes out of the other portal of the same colour, the same way.
Magic whirl: bends the flight of a ball that comes near it.A bonus sometimes falls out of a broken block. Catch it with your paddle.
Burning cannon ball: the ball flies through the enemies.
Three cannon balls: you play with three balls at once.
Log: the ball sticks to the paddle until you release it.
Plus: the paddle gets longer for a while.
Sheep: the ball slows down.
Meat: one more life.
Arrows: the paddle shoots arrows.
Gold: +100 points.
Snowflake: the whole army freezes for 8 seconds.
Arrow up: the army steps back twice.
Volley: an arrow falls on every unit of the army.
Shield: for 20 seconds a unit that reaches the palisade burns nothing.
Minus: the paddle shrinks for a while.
Acorn: the ball speeds up.
Big cannon ball: the ball grows.
Arrow down: the army steps forward at once.
Bomb: one of your lives is gone.