Henk and Alexey want an incontestible lock on the Tetris IP, and have employed a strategy of total lawfare to defend it, claiming any form of IP -- copyright, p

Henk and Alexey want an incontestible lock on the Tetris IP, and have employed a strategy of total lawfare to defend it, claiming any form of IP -- copyright, patent, trademark -- over any aspect of the game, and using any legal tools available to enforce their ownership of said IP. This includes getting CBP to seize imports of unlicensed Tetris games, firing off DMCA takedowns, and -- doubtlessly -- venue shopping for a sympathetic judge should they actually decide to litigate. This is why you do not clone Tetris without authorization. They have better lawyers and the will to destroy you if you do.