- background: https://opengameart.org/content/space-background-7
- enemies (orbs), bomb, rocket, flame, explosion: https://opengameart.org/content/superpowers-assets-various-2d
- energy, hearts: noto sans color font
- player ship: https://opengameart.org/content/space-shooter-art
- music: https://opengameart.org/content/szymon-matuszewski-space-chase
- various sfx: https://opengameart.org/content/sound-effects-mini-pack15
- rocket thrust: https://freesound.org/people/qubodup/sounds/171106/
- ship thrust: https://freesound.org/people/hykenfreak/sounds/214663/
- enemy collision: https://freesound.org/people/adcbicycle/sounds/14056/
- music: https://patrickdearteaga.com/arcade-music/