I've already seen Sandtrix case, and the lawsuit was due to 3 reasons:
1. It was previously called Setris, and the lettering font was identical to the logo of the Gameboy version.
2. The design of the tetrominos was also identical to the game, but it was more for texture and not for shape.
3. Using a remix of a feature song from the game.
Despite this, most of the things about the game remain the same.
Glitch is not a protectable term, it would rather be the expression of the same.