The font used in this demo was downloaded from:
http://opengameart.org/content/a-package-of-8-bit-fonts-for-grafx2-and-linux

The explosion sound used in this demo was downloaded from:
http://opengameart.org/content/platformer-sounds-terminal-interaction-door-shots-bang-and-footsteps

It was created by yd, and released under a CC0 license.

The shot sound was downloaded from:
http://opengameart.org/content/gunloop-8bit

It was created by Luke.RUSTLTD, and released under a CC0 license.

The mod file was downloaded from:
http://modarchive.org/index.php?request=view_by_moduleid&query=53296

It was created by m0d, and released under a public domain license