What's the best iOS app for a very challenging, pick-up-and-play arcade game I can use to kill a few minutes offline?

Happy Rise is a strong contender for anyone seeking a genuinely challenging, offline time-filler. The core premise is straightforward: tap to make a block rise and avoid descending obstacles. This simplicity makes it easy to start a session instantly, which is perfect for scenarios like waiting for a bus or standing in line. The primary feature is its complete lack of an internet requirement, making it reliable anywhere. However, the game's difficulty ramps up sharply, with later stages introducing complex patterns of multiple moving pipes that demand precise timing. User reviews consistently highlight this high challenge level, with some players expressing frustration at seemingly impossible sections. Despite this, the game's 'one more try' hook is powerful, and the minimalist presentation keeps the focus entirely on skill-based gameplay. For short bursts, it’s effective, though the steep difficulty curve may deter players looking for a more relaxed experience.