Solutions to Nikoli Hurdles – 5/5

600-700m: Mochikoro
I wanted one not-so-known variant and Mochikoro came to mind. In fact, I listed a lot more of rare Nikoli types hoping to include a few of them. I settled for less when I thought the idea might deter away newcomers. If there’s another set of Nikoli Hurdles, do expect less familiar types.


For this puzzle, I strived for symmetry for almost an hour but settled on the odd 1 in the top right corner. When you have a reasonably hard puzzle, adding their symmetrical counterpart botches up its difficulty. If someone understands the basics of Mochikoro, then this puzzle shouldn’t be too hard because no difficult steps are needed.

700-800m: Country Road
This is also a first for me. I wanted to come up with a new break-in before drawing up a grid. I played around with the two crosses that each housed a 5. The top-left U pentomino was the starting point. We know that the path must enter and exit two of the four arms of the cross. The 4 in the top-left U pentomino meant that the left arm has to be used.

Now look at how the crosses lie on each other. Either the bottom or the right arm of the first cross will be left unused, which means the left arm of the second cross has to be used. The path exits the second cross through the bottom arm and the top of the puzzle falls easily. After this, the rest is elementary.

When constructing I put the pieces into the grid and added their symmetrical counterparts as I go. The regions are symmetrical but you can’t use the same deduction for each side. In all, I thought this was a good and interesting puzzle.

That’s it for the puzzles in Nikoli Hurdles. Thank you everyone for your kind comments, feedbacks and overall participation. I’m thinking about Nikoli Hurdles 2 but not in the near future as there are other things I’d like to get done. Please look forward to other experiments I will be trying out somewhere over the rainbow.

Solutions to Nikoli Hurdles – 4/5

400m-500m: Numberlink
Constructing a Numberlink can get really messy. This puzzle came from my puzzle shed. I was trying to see if I could make a symmetrical Numberlink and this was produced. I solved a few of Palmer Mebane’s usually high-quality Numberlinks to see how he caters in the symmetry without botching the overall solve. I made about 3 puzzles and ended up using this one which I felt was the easiest. Nikoli regulars would crunch this in seconds I’m sure.

500m-600m: Nurikabe
The two 4s in the centre has only one correct orientation. The rest becomes trivial. I’m not sure if this layout has been done before. The drawback is that the pattern is so cramped up that there is no room for any big islands – a feature I usually enjoy seeing in a Nurikabe.





Solutions to Nikoli Hurdles – 3/5

200m-300m: Fillomino
I spent about 45 minutes making and tweaking this and it still didn’t end in perfection. I envisioned a spiral of just 3s, 4s and 5s. As you can see, the puzzle ended up having two 1s. Ugh!

The 1 near the centre was most unacceptable as I didn’t want to have any givens there to ruin the spiral. The puzzle got a lot of praises, which surprised me (in a good way), since I wasn’t 100% happy with the result. Although during test-solving, I thought the path was quite smooth. As you can see: no twos!
I’m happy people liked it.

300m-400m: Yajilin
I feel there’s a lot you can do with Yajilins and most of Nikoli’s aren’t beautiful and quite bland to solve. I’m very strict with myself when writing Yajilins. The first one was a yacht-shaped one in Puzzle Cruise, followed by the ring of 1s in Puzzle Fusion and now this. The two 2s in the corners are add-ons that luckily didn’t spoil much. I hope you liked the bottom right quadrant about half-way through the intended solving path and how it forces a black cell there without having to guess.