This is a puzzle game. This is supposed to be where it's all at. Gamers don't look for deep stories in a puzzle game. There's a reason for that. If anything, the 'story' gets in the way of the game. Unfortunately, that's not all.
Remember the old Tetris? Remember rotating that piece at the last second to fill that hole? There's a delicate balance in that ability. I've played 'tetris-clones' before that don't have that ability at all and they are, quite frankly, an aggravation to play. Tetris Worlds errs on the other side, allowing a player to simply sit there and spin a block indefinitely, as long as they don't wait too long in between flips. If you're doing poorly (or your opponent is doing even worse) and you want to just sort of 'wait them out', you can sit there and flip your piece as long as you like and wait and see what happens. This turns out to be more of an aggravation than a benefit. Additionally, while there are several different 'flavors' of Tetris offered here, most of the variations aren't truly an improvement. If, however, you like Tetris and you're just tired of the same-old-same-old, then you may want to give Tetris Worlds a try.