If you become a member, you have access to puzzles from the previous month (starting from the 11th of each month). We will make newly released puzzles available for 180 days, so if you are a member for 5 months, you will have 800 original problems to do anytime.
In Shakashaka you place black triangles in the white squares (not more than one in each!) of the grid. The remaining white parts of the grid must form rectangles or squares. Enjoy the fun of solving a Shakashaka.
Shikaku is another original Nikoli puzzle, which provides a special sense of solving while complying with a very simple rule. Shikaku is also a great math trainer for kids. While playing the game they learn multiplication such as a 12 can be 1x12, 2x6 or 3x4. And if you get stuck, look at the puzzle from a distance and you will soon find the next rectangle.
In Hashiwokakero you are the king of the islands, and your job is to connect the islands according to their populations - small islands need only one bridge (it says 1 in the island), and larger islands need more bridges (the number in the island). Then remember that this is all one kingdom, yours, so you must make it possible for all the citizens to travel between all the islands.
Numberlink is a puzzle where you connect pairs of numbers with a continuous line. This puzzle requires inspired guessing and puzzling sense. Don't worry about mistakes. Draw the lines like you think they fit. That's how to make it enjoyable!
As a beginner you need to add and subtract, but when you get used to Kakuro you will learn to rely more on logic and less on calculations. You'll be amazed at how fast you improve. And the interesting thing about this puzzle is that beginners and experts are able to enjoy the same puzzles.