Ok I read carefully all your answers, thank you so much, it's very clear and specific.
Which it leads me to ask 2 more questions :
1) Is there a difference between a copyright or a patent ?
Or is just a way to speak ?
2) If I try to make a template inspired by famous games, taking the max of precautions, but unintentionnaly, I infrige a copyright or a law, etc.
My question is : are they going to warn me first and ask me to stop the sales and retire my template or my game from the market ? OR are they going IMMEDIATLY to sue me ?
Because despite my efforts to follow the rules, of course I will retire my product if they ask me to. But I want to be sure to be warned first and not be pursued !!
Thanks for your answers ;)
From my personal knowledge (not a fully fledge patent person or copyright person, just self informed, i might be wrong, but again this is how i understand this 2 things), a patent applies to physical products and software that was never done before and the person that did it "invented it for the 1st time" like ... "attaching a zipper to a hoody to take off your sleeves" or "develop the first cryptocurrency" if the bitcoin people did a patent ... no other cryptocurrency would be alive today, but luckily they didn't ;) to get a patent you have to spend a lot of money and time and you need several people to do "official documents, drawing schemes, how things work etc" price varies from country to country.
Copyright is a "Artists type of similar protection" being it a book, artwork online etc. the moment you published something original you are covered/protected. now not sure how you prove your rights on the copyright.. its a bit confusing, cause no other company, like in the case of the patent, says "yea this dude made it first and has the rights to it, and we are witnesses, and this document proves it".
but i think you are safe, considering your game of choice to "clone" its a generic sidescrooler, even construct comes with a "Example template" by default... so i don't think they will sue you for gameplay "similarities" but they can for graphics and characters that look the same, story line etc.
as per your last edited question: they will warn you first and ask nice to take it down, or have a meeting with them and share some revenue or pay some "non-exclusive license fee" it usually how it eventually settles in most cases.
my personal advice, try contact the original developer, see if they offer a non-exclusive license, for you to be able to use that gameplay concept, since you are not buying a license on the actual source file of the game they made, the price for it, will probably be in the range of 3-4 digits.
On other aspects, just ask a lawyer that is working with this type of stuff.
Hope it answered your questions