I don&#x27;t know if you&#x27;re actually interested in the theory behind analyzing game complexity or just trying to be negative without doing your homework.<p>Classifying traversal and 2-D games is not a new thing, and they simply apply previous methodologies and proofs to classic Nintendo games. They do not do this via &quot;proofs by obscurity&quot; but rather by classical NP-Hard proofs built upon previous theorems. Specifically, I will point you to the following two papers on fundamentals of proving NP-Hardness of 2-D and traversal games respectively:<p>- <a href="http:&#x2F;&#x2F;link.springer.com&#x2F;article&#x2F;10.1007%2Fs00224-013-9497-5" rel="nofollow">http:&#x2F;&#x2F;link.springer.com&#x2F;article&#x2F;10.1007%2Fs00224-013-9497-5</a><p>- <a href="http:&#x2F;&#x2F;link.springer.com&#x2F;chapter&#x2F;10.1007%2F978-3-642-13122-6_22" rel="nofollow">http:&#x2F;&#x2F;link.springer.com&#x2F;chapter&#x2F;10.1007%2F978-3-642-13122-6...</a><p>They chose the collection of games because of their relevance to the authors. They wanted to study classic Nintendo games. Other games have also been studied including some, if not all, of the games you mentioned. If you did your research, you would already know the answers to the complexity of games like Tetris or Pong.<p>If you&#x27;re genuinely interested in the underlying proofs or the theory behind game complexity, I urge you to read through the papers and their citations first before jumping to conclusions.