Foreword: Everything about laws will always be in a gray area, because the result of a case finally comes from a handful of people.
Others have pointed out accurately that game codes and assets are subject to copyright and that the names of products, companies, and so on. under trademark law.
However, while others have pointed out that it is impossible to protect gaming mechanisms by copyright, this is not 100% true.
Let's look at the legal history of Tetris, a game often cloned by new developers.
In mid-2006 and at the end of 1997, TTC's legal counsel sent stop letters to websites based on Tetris-type games infringing the "Tetris" trademark, the commercial make-up and / or "copyright". Around 2009, TTC and Tetris Holding LLC filed a lawsuit against BioSocia, Inc. on the grounds that BioSocia's "Blockles" game violated the property rights of TTC and Tetris Holding LLC. On September 10, 2009, the lawsuit against BioSocia was resolved. BioSocia has agreed to stop making the game "Blockles" available to the public. In May 2010, TTC's legal counsel sent a termination letter to Google, in which he insisted that 35 Tetris clones be removed from the Android Market. In June 2012, a US District Court judge ruled that Xio Interactive's "Mino" Tetris clone infringed Tetris' copyright by reproducing elements such as playground dimensions and form blocks.
Tetris and Mino
Are the game mechanisms protected by copyright? The answer, as with many legal questions, is may be.
Learn more about Mino vs Tetris here.