The Upgrades Screen of the menu is where you can upgrade sixteen different parts of the game.
You can purchase a unit with the given amount of rubies. The costs are:
- Warrior: Starter; free
- Ninja: 1 Ruby
- Gunner: 3 Rubies
- Cannon: 10 Rubies
- Black Wizard: 20 Rubies
- Dark Angel: 40 Rubies
- Golem: 70 Rubies
- Green Goblin: 100 Rubies
After purchasing the unit, you can use gold/rubies to increase power and health.
You can also upgrade the bow or damage resistance of the castle here. All of them require gold.
- Damage: Increases damage given to enemy units; may increase the number of arrows in one throw or set them on fire.
- Range: Increases the maximum length of the bow range.
- Fire speed: Increases fire rate.
- Castle HP: Increases the health of the castle.
The last four increase various areas of the game, giving you an advantage.
- Gold: Increases amount of gold dropped by enemy units when killed.
- Mana-1: Increases maximum Mana.
- Mana-2: Increases speed of Mana generation.
- Cool time: Decreases the cool time for unit cards.