Is there a way I can withdraw my entry for the Time Attack Contest, Tunnel?

There is no way to withdraw your entry by yourself but you can update it.

why is your file only 160kb? you have 1.5Mb available!

I still don't know or understand file size is seems. It was telling me my picture was not wide enough. I tried to make the picture bigger by resizing it but it went blurry. I also tried some other stuff but still got worse. I'm still trying to figure it out.

an image saved in a small size format can't be resized bigger without loosing quality, this is what happens to your chop. When you download the source keep its size and don't shrink it till the end and only if necessary (kb size). Look for large format images on the web and shrink that to fit the source if needed.

Your next problem will be the kb size

I'm not exactly tech savvy. But will see what I can do....

For any questions write in the forum, me and other users will be happy to help you. Keep up the good work!