To what extent is Tetris (on Game Boy) a game of luck?
Newer versions of Tetris use "bags" to ensure that you don't go too long without getting a particular piece again. However, many older versions of Tetris, such as the Gameboy version, produced pieces at random (With a bias against getting the same piece in a row,) so long droughts without a critical piece can occur.
An example can be seen in this video (This is the NES version, but I believe the Gameboy version works similarly):
In short, I think it's fair to say that the Gameboy version of Tetris has a significant luck component.