This is nutty, I love it. One word of caution, I wouldn't mention the word Tetris anywhere, just use "falling block classic game" or whatever else, as it's one of the most trigger happy IP I know of after Nintendo. That said it's so far detached from the original you might be fine.
so your advice is basically, go ahead and make your derivative tetris game but just call it something else?
Every game is derivative.
Almost every human thought and action is.
The language you speak. Your opinions. Even your preferences are shaped by things you've seen and copied.
If you said that every game (or whatever) must pay the predecessors for every mechanic they reused, we'd be left with nothing but taxes to be paid to the dead and retired. Those no longer carrying the torch forward.