Tower defense · Mobile

Castle Defense: Monster Siege

Build. Defend. Survive.

The monster Horde has crossed the border. Rally the archers, raise your towers, call in your heroes, and hold the line all the way to the King's chamber.

Monster Siege key art: the Horde attacks the castle walls
Trailers

See the siege

Story trailer

Choose your heroes

Mini-games

About the game

Hold the line

Monster Siege is a tower defense game for smartphones, illustrated in an ink-and-watercolor style. Across a 20-level campaign you defend the kingdom from the Horde of the goblin warlord Rex Goblin: from the village fields, across the Silver River and the mountains, to the Great Wall and the capital itself.

Every battlefield has its own terrain, and some towers can only be built on certain ground, so reading the land matters as much as choosing your defenses.

  • GenreTower defense
  • PlatformAndroid · Google Play
  • Campaign20 levels
  • StatusComing soon

20-level campaign

From the outer villages to the final stand in the King's chamber.

Four heroes

Archer, Frost Mage, Hammer and Assassin, each with their own role.

Terrain matters

Each tower type needs the right ground. Plan your build around the land.

Mana & spells

Turn the tide with magic when the Horde breaks through.

Mini-game levels

Optional challenges and a world-map shop to upgrade your defense.

Six languages

English, French, Spanish, Portuguese (PT and BR) and Japanese.

Battlefields

From the village to the throne

Each level is its own illustrated map. Tap to enlarge.

World map
Level 1 · The village
Level 20 · The King's Chamber
Interview

Inside the siege

Bernardo Malafaya

Bernardo Malafaya

Creator of Castle Defense: Monster Siege

Monster Siege is your first game. Why tower defense?

Tower defense is the perfect place to learn how games work. The rules are clear, but every level can tell a little story. I studied the best tower defense games and asked myself what I could add: a richly illustrated world and a story you actually care about.

You come from film and advertising. How did that shape the game?

I think in scenes and characters first. Before I designed a single tower, I knew who Arthur was, who the King was, and why Rex Goblin wanted the crown. The trailers and cutscenes are directed like short films, because that's my language.

What makes Monster Siege different from other tower defense games?

The art and the terrain. Every map is a full illustration, and the land itself decides what you can build where. You can't copy the same strategy from one level to the next; you have to read the battlefield.

You also made the music and the artwork yourself?

Yes. Doing the music and art myself means the whole game feels like one voice. When the Horde arrives, the music, the colors and the gameplay all push in the same direction.

What's next for this world?

The siege was only the beginning. Not everyone who fell from the walls stayed down, and that's where Arthur: The Crown of Rex begins.

Lore & mythology

The Chronicle of the Siege

The kingdom had known peace for a long time. Farms filled its valleys, fishing villages lined its lakes, and from the capital the King ruled behind walls that had never fallen. Then the fires appeared on the border.

The Rise of Rex Goblin

In the dark lands beyond the hills, one goblin rose above the rest. Cunning, cruel and endlessly ambitious, Rex Goblin united the scattered tribes into a single Horde of goblins, trolls, ogres, shamans and beasts. His goal was the capital, and the crown of its King.

The Defense of the Realm

Against the Horde stood Arthur, commander of the kingdom's defense. When the militia lost its nerve, he rallied the village archers. When goblins built rafts and swam the Silver River, he held the bridges and sank their boats. The monks of the hidden monastery sent him their Frost Mages, and the brethren of the forge gave him the power of the Hammer, to crush armor no arrow could pierce.

Gorrak at the Great Wall

Halfway to the capital stands the Great Wall. There Rex Goblin sent his elite shock troops, led by his Dracon, Gorrak the Wall Breaker, a towering dragon-blooded warrior whose roar drove every monster around him into a charge. No wall had ever stopped him, and the kingdom was about to learn how he earned his name.

The Siege of the Capital

The Horde broke through the outer walls and the fighting reached the castle courtyard. Arthur covered the people fleeing to the keep and held the last oak doors. But Rex Goblin himself reached the King's chamber, and the fate of the kingdom came down to a single room.

When the war was over, Rex Goblin's banner lay in the dust, and Arthur was named the Shield of the Realm. But one question remained: where was Gorrak?

Arthur
Commander

Arthur

Leads the kingdom's defense, from the village fields to the King's own chamber.

The King
The Crown

The King

Rules from the capital and trusts Arthur with the fate of the realm.

The Archer
Hero

The Archer

The village archers and the Guard, the first line against the Horde.

The Frost Mage
Hero

The Frost Mage

Sent by the monks of the hidden monastery to chill the Horde's advance.

The Hammer
Hero

The Hammer

The forge brethren's heavy hitters, for armor that arrows can't pierce.

The Assassin
Hero

The Assassin

Strikes from the rooftops and shadows where the Horde least expects.

Gorrak the Wall Breaker
Horde

Gorrak the Wall Breaker

Rex Goblin's Dracon. His roar makes nearby monsters charge.

Rex Goblin
Horde

Rex Goblin

The goblin warlord who united the tribes and came for the King's crown.

The story continues

Gorrak survived the fall. And he wants the crown.