These are a couple of 512x512px icons with a 3D effect for the game N by Metanet. They come in two colors (black and yellow), two versions (with and without shadows), and three formats (png, icns, and ico).
License & Credits: These icons are free for personal use only. They are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License. I am not affiliated with or endorsed by Metanet. N and the N logo are the registered trademarks of and copyrighted by Metanet Software Inc.