Indeed very similar, most likely from reusing the same codebase.
But it adheres to the main theme very well.
I remember playing global game jams with the theme "wave" and we decided to use "sound wave". I literally copied one of my teammate's sound processing code (in js) and slapped into my phaser.io codebase (also js. The platformer logic came from watching a tutorial on the fly)
It saved massive time and we were able to finish making the game: A platformer with platforms controlled by singing to the mic. (note: Wrestling with the HTML5 audio API isn't fun)
My artist drawn completely new set of assets just for this theme, and my other friend (who gave me the audio code) did not actually participate in the jam. The platforming code and the game logic (and difficulty tuning and design decisions put into the thing) were all new, inspired by the theme and made just for the theme.
You are still free to say that he cheated, but I see it as reusing some hard work and making substantial work (look at the bullet hell choreography! Compare that to the crappy Nier Automata bullet hell) to make it a completely new game.