Yes. I love to play it in the metro/subway alternating with Dungeon Raid. Time passes by rapidly with such exciting and elegant games (faster than the express train) so I always have to take carefully precautions (GPS alarm app) for not missing my station.
Don't be scared by the poor user ratings in the tA OP at the top, folks. Get it if you don't have it already. Recommended & clever-clever puzzle with elements of Bejeweled, Tetris, Drop7… (It's free every one or two months for a few hours or days.)
Maybe you'll need two or five minutes—stupid me: six—to comprehend the special game mechanics (there is a good animated and short tutorial inside) but then it's a blast! There are very attractive looong and essential chain reactions.
You're getting better with almost each attempt. Promised! And there is a VERY motivating and epic dramaturgic (but not disturbing) realtime information alert when you beat your highscore once again. Your hard job is nothing more than choosing the best column. Done.
Rare and precious nowadays: No IAPs, no ads, full straight version. A good puzzle doesn't need more than seven pieces of megabytes. And I am pretty sure those are pure retina graphics here on my iPad 3rd gen.
Enjoy if you love challenging casual puzzles, pretty abstract and simple. Okay, kind of… Love it when it plays from alone in the menue screen. Have a look in the settings.