The background music is made by Kat and published here: https://opengameart.org/content/title-theme-8-bit-style The landing sound is from a soundpack by Little Robot Sound Factory, you can find it here: https://opengameart.org/content/8-bit-sound-effects-library
The font is Russo one, it was originally published here: https://www.dafont.com/russo-one.font