Tetris but predictable. It's basically a novelty flash game which has probably already been done. It's not offensively bad (or as the name would imply, "terrible") but it stops being interesting about 3 minutes in

EDIT: Apparently this game actually changed like every week and I just caught it on a boring one? (it just gave you the same piece over and over again, see: https://youtu.be/sxylFvvCXKs?t=120) It's been stuck on a "floor is lava" one for like 2 years now though. It's still novelty tetris that is only interesting for a couple minutes though, and not being able to select a variant is pretty silly