Copyright does not protect rules. A new game can use the same rules. However, copyright does protect the exact words used to express the rules. So the rules must be rewritten to have the same (or a similar) meaning, but using different words. Or the rules may be changed in whatever way you choose. Since rules are not protected by copyright, changing them does not crease a derivative work.
Graphics and images may not be copied without permission. The designer of a new game will, to to create or obtain new images. (Exception: images already in the public domain, like many NASA images.)
The price charged, if any, does not affect whether something is a copyright infringement or not. If the new game is not an infringement when free, it is still not an infringement if you charge for it.
The name of the old game is probably a trademark. You may not use it in such a way as to suggest that the new game is from the same source, or is approved or endorsed by the makers of the old game. The old name may be used in a comparison to the old one, but only if it is very clear that they are different and from different sources.