Originally Posted by NetAtom Ideas can be copyrighted.

Not to try to pick a fight or anything, but that's actually incorrect. Also, most places internationally abide by the same rules. For example,

Here's the "official" answer from www.patent.gov.uk in relation to rules in the UK:

"...So the above works are protected by copyright, regardless of the medium in which they exist and this includes the internet. You should also note that copyright does not protect ideas. It protects the way the idea is expressed in a piece of work, but it does not protect the idea itself." Here's a direct link to the page if you want to see what is covered by UK copyright protection: http://www.patent.gov.uk/copy/definition.htm

Here's the "official" answer from the US Copyright office:

"How do I protect my idea?
Copyright does not protect ideas, concepts, systems, or methods of doing something. You may express your ideas in writing or drawings and claim copyright in your description, but be aware that copyright will not protect the idea itself as revealed in your written or artistic work." - Found in the agency's FAQs.

I'm not a lawyer, but I am extremely versed in US copyright law. I also occasionally work with artists overseas, and these are the kinds of questions I have to answer regularly. Most of my clients are musicians, so as you can imagine, we're forced to work through issues such as these on a very regular basis. Please understand that ideas, names, titles, and other similar things can NOT be copyrighted in any way. Only the process by which the idea is carried out (in this case your code), or something physically created from the idea (in this care, your graphics). There's nothing you can do just because someone used a very similar, or even the same, idea.