Yes, the other modes as well as the nostalgia factor make the game worth it. It's only classic Tetris that was broken.
You can spin the blocks indefinitely unlike what 31 Flavas said, in offline mode. I believe they still lock after a time in online mode.
No, this was not a Photoshop, and although I consider myself good at Tetris, that really had little bearing on my ability to do what I did.
There is another thing that I consider broken about the game compared to classic Tetris: not only can you spin forever, but the way certain pieces rotate allows you to actually climb back up the stack!
Other things that don't necessarily break the game but make it much less of a challenge include the ridiculous number of next blocks, the ability to hold a piece, the fact that all blocks start at the same orientation, and the fact that blocks start off of the top of the screen. They put in options for Ghost Piece and Hard Drop, so I don't know why they couldn't have put in other options.