land.png generated from https://cpetry.github.io/TextureGenerator-Online/
Licensed under MIT at https://github.com/cpetry/TextureGenerator-Online/blob/gh-pages/LICENSE

noise.png generated from https://giggster.com/guide/cloud-texture-generator/

KettleParallaxNeb.png and KettleParallaxBG.png adapted from Screaming Brain Studios CC-0 https://opengameart.org/content/seamless-space-backgrounds