Kuru Kuru Kururin

Kuru Kuru Kururin is a puzzle game developed by Eighting Raizing for the Game Boy Advance, released in 2001.

In the game, you control a little bird called Kururin in his stick-shaped helicopter, appropriately named "Helirin", in a quest to save your siblings. Yes, it's that kind of game.

The gameplay consists of maneuvering the ever-rotating Helirin through many narrow passages, moving obstacles and stationary turrets. In the story mode, you need to steer your Helirin through 10 stages (with names like Cake Land, Star Land and Cloud Land), each with three levels that you need to finish in a linear fashion. Then there's the Challenge Mode, which has 50 very short challenge levels that are appropriately very difficult.

The game also has two sequels that appeared only in Japan: Kururin Paradise (GBA) and Kururin Squash! (Game Cube).

Then there's Hare T, Hare P and Hare M. At the beginning, there's only Hare T on the high score table and if you beat one of the Hares, you can see the next one's times. And Hare M is incredibly hard to beat.
 * Brutal Bonus Level: If you finish every single one of the 50 challenge level without getting hit (which is quite difficult), you unlock 5 more challenge levels, each of them very difficult.
 * Difficulty Levels: There's an "Easy" and a "Normal" mode. In Easy mode, the Helirin is half the size, making every level so much easier.
 * Excuse Plot: Yes, you see your siblings in level 3 of each stage, but all you do is pick them up, get to the end of the level and that's it.
 * Self-Imposed Challenge: The game encourages these because if you go through a level without getting hit, you get a star in that level. Get a star in every level and you unlock an extra stage with three very long levels.
 * Surprise Difficulty: The game looks extremely cutesy, but the later levels get very difficult. And don't even get me started on the Challenge Mode...