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.
The game lifts a lot of design elements from the Game Boy version of Tetris. Clearly to evoke the nostalgia. Down to specific graphical elements like the style of the blocks and fonts used.
The Tetris Company would have a point here. The game wants you to think of a very specific version of Tetris. I forget where Nintendo exactly was involved in the game, but it’s possible they hold some rights to the Game Boy version as well.
I’d strip out all the Game Boy elements. I doubt you’d get by on a parody claim.
Same with the Zelda word...
Trademark infringement is a bit different, since there’s no analogue to the dmca process. But it’s pretty reasonable to want to avoid the hassle by just changing a few words.
(What is the expected litigation route for trademark claims anyway? Can they knock a project offline, or just send a strongly worded lawyer letter?)
IANAL, but I would expect a cease-and-desist letter or the national equivalent depending on the country you're living in. Usually you have a short delay to remediate, or risk getting sued.
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.