Source code by David Thompson - GPLv3+ Sprites by David Thompson - CC BY-SA 4.0 International KenPixel Mini font by Kenney - CC0 - http://opengameart.org/content/kenney-fonts Music by Juhani Junkala - CC0 - http://opengameart.org/content/5-chiptunes-action Sounds by Little Robot Sound Factory - CC-BY 3.0 - http://opengameart.org/content/8-bit-sound-effects-library