Zombie assets: https://free-game-assets.itch.io/2d-zombie-free-sprite UI assets: https://gamedeveloperstudio.itch.io/ui-icons
Textures from https://cga-creative-game-assets.itch.io/gold-2d-mobile-ui-for-casual-game
Coin https://opengameart.org/content/coin-animation
Bone https://opengameart.org/content/throwing-bone
The turret textures were created by Chun Ho Choi. Please contact him for license details.
The catapult textures were created by Caleb Smith. Please contact him for license details.