I am planing to develop a game, in fact a puzzle game, I have changed the graphics but the level design is all the same. For example, the original puzzle game have five aliens as the obstacle in the human way to airship, the aliens spit fire on human. So here I have changed the alien to chameleon, with same positions(the aliens position never change so as the chameleon's ) and exact strike range(stick its tongue out to catch) and exact measurement(tile) and also converted the human to honey bee. So my doubt is that will there be any issue on this, for I am rendering the exact level design? ( I have searched, but didn't get a precise answer for my doubt)
First: I AM NOT A LAWYER, THIS IS NOT LEGAL ADVICE.
Second: I recommend checking out this question:
I think it is important to note here that 'They' can sue you for really whatever they want in terms of Copyright. Of course, you can get a frivolous case thrown out, but all they need is reasonable belief that you infringed upon their intellectual property to file suit at that point it becomes your legal department against theirs.
When you copyright something, you copyright the execution. Either way, it seems that you would be straddling nicely on the bounds of a lawsuit.
Of course, there is also the Copyright and Trademark office's new-ish stand on being able to copyright game mechanics. So like all legal questions, the best advice I can give is that you GET A LAWYER.
Oh and remember, even if the game mechanics can't be copyrighted, they may still be patented. Likewise, they could also have a design patent on how stages are set up.
You may possibly. I am not entirely sure, but to be completely safe it could be good to alter the positions as well.
Then there is no way there can be any legal doubts, since you're just developing a game similar. ;)
I don't think they can sue you over positions. They don't own those pixels and as long as you're not using any of their code/assets/names etc you are fine.
While the other answers support the idea that the legal issues are a bit vague and you're probably fine, there's another issue here. Ethically, this may be plagiarism. If you're doing this as an exercise to improve your skills, or replicating a game that is no longer available, it might be fine. But if you're making a game for general release for love or money, this is a bad idea.
The players who would like your game are likely to have played the original, and if they liked the original, they're probably going to think badly of you for having copied it. If they didn't like the original, they won't like your game anyway. It's far better, in my opinion, to expand on the original game with your own level designs and maybe some new gameplay elements. From an ethical perspective, it's also a better idea not to lift so directly from another person's work.
Any good answer would require discussing the precise nature of the existing work as well as your intended use. The three types of legal protection you should consider in the US are copyrights, patents, and trademarks. Trade secrets should not worry you unless you are truly a badguy and have stolen inside info, for instance by hiring away a former employee / consultant of your competitor and pumping them for it.
Game graphics, text, music, and the like are subject to copyright in most jurisdictions, including the US. Original computer code is always copyrighted, without any further action on the author's part. Affixing an original work to a medium is all it takes to create a copyright in the US -- registration is helpful for various purposes (such as to document a security interest for a loan, or to fix a date for litigation purposes) but not necessary. A game design may be patentable if it is sufficiently novel and non-obvious, but a game design or mechanic is not automatically self-protecting as such without a patent application. Very few computer game makers seek specific patents on individual game designs, although an increasing number of major companies are patenting generally useful game-related mechanisms (wiimote-related stuff; gesture controls; etc.). Interestingly enough, board games are quite frequently patented, and in fact it is easier to patent a board game design than it is a more free-form computer game. Trademark protection could apply to distinctive characters (Mario & Luigi) and the game's packaging itself (the look of the "box" or website delivery and advertising scheme).
You can avoid running afoul of copyright protection by making sure to, among other practices: never use code from another game without a license, and always vet your third-party / outsourced code with a plagiarism detector; always write your own music or license it officially; create your own art assets or license them; if you are including referential material, make sure it is clearly a satire/parody or otherwise fits within a legal exception. For patents, unless you know of a patent that reads into your area, you should probably use your instinct as to whether your game mechanic is ripping off another developer. For instance, just b/c Donkey Kong pioneered the platformer mechanic does not mean that all future platformers had to license the idea; it is safe to assume that game design involving jumping and dodging is not in fact patented or patentable. The reason that most people do not conduct an exhaustive search for infringed patents before building something is that there is a huge sea of patented material out there, and if you knowingly infringe on another's IP, you can be subject to a claim for treble damages, whereas if you unknowingly happen to infringe a patent that you were not aware existed, you are only liable for 1X damages and therefore a license negotiation will be much more favorable to you. Finally trademark -- avoid using art assets in the game, and external marketing / packaging, that is confusingly similar to your competitors'.
I see a lot of amateur legal advice in response to these kinds of questions in forums, and it is usually hit or miss. At the end of the day, if you are really concerned (and it sounds like perhaps you should be) you ought to discuss the specifics of your case with a knowledgeable lawyer. If you can change a few things so you are not so closely mimicking another game, then perhaps that will be easier and cheaper than hiring a lawyer to analyze a close call scenario.
Hope that was helpful.