English Country Tune for iPhone and iPad has got to be both the best and most challenging puzzle game I've come across on the iPhone or iPad to date. There are 17 different worlds, each with their own objectives and filled with 3-dimensional levels.
So far, I've mainly spent my time in two worlds: Larve and Adv Larva. The objective in both of these worlds is to move the spheres, called larve, into the cubes, called incubators, by directing the flat square along the world to push the larve to where they need to be. The levels start out easy and primarily 2-dimenional, but quickly turn into challenging 3-dimensional puzzles that really makes you think. When pushing a larve over an edge, the direction it moves is dependent on how your square is positioned when it pushes it. It's hard to explain, and the way the game described this rule was a bit confusing, but after some experimentation, I was able to figure it out. Some may find this irritating, but it honestly didn't bother me because, to me, figuring out the rules and patterns is part of the puzzle.
It's hard to describe in words what the gameplay of English Country Tune is like, so please check out the video of the game in action below. I've only seen a small part of what this game can offer, yet already know that English Country Tune is a game I will enjoy playing for a very long time. It requires an immense amount of analytical skills -- and as a mathematician, I really appreciate this attribute. But I did warn you -- it's hard.
You don't play English Country Tune to have fun. You play English Country Tune to be challenged. To exercise your brain. To feel that immeasurable amount of satisfaction and pride when you do complete a level.