A simple NES arcade game by Łukasz Kur and Ryszard Brzukała of emunes.pl
This simple NES game was written for a charity auction and is now available for download as public domain asm source. The game itself can be played online at http://emunes.pl/grunio/. The .nes file is also included.
The code also includes music tracks by Ozzed. These are licensed under CC BY-SA 3.0.