I'm of the personal opinion that sometimes our most powerful methods for LDing are ones that we make up ourselves or other people's that we've at least tweaked. So sure, if you can make a mental link between tetris preceeding sleep and dreams, then it could be your personal dream cue. Everytime you play tetris during the day, you could do a RC after to reinforce this. Or you could focus on the tetris shapes when going to sleep after a WBTB and let that become hypnogogic images to use for WILD. Or whatever you can think of or something else completely