Ouverture Facile

In case you enjoyed our exciting puzzle crime story “Detective Sanders and the Zodiac Killer”, you may want to try some other similar browser puzzles. One of our favorites is “Ouverture Facile” (“Easy Opening” from French), consisting of over 90 different levels. Test your puzzle skills by clicking the image below and see how far you can get. After you finish with Ouverture Facile, you can check also “Notpron”“God Tower”“Weffriddles”, and “The Python Challenge”.

The Zoomquilt

You may not know this, but we have a strange penchant for optical illusions, fractals, and other mind-perplexing images. That’s why we got so impressed when we saw for the first time the “infinite-zoom” artwork by Nikolaus Baumgarten. Bearing the suitable name “The Zoomquilt”, this seemingly never-ending image instantly became our favorite screen-saver. Take a look at it by clicking the image below, and if you like it, make sure to search YouTube for other similar illustrations.

Parable of the Polygons

Parable of the Polygons is an interesting analysis of diversity in society, beautifully presented through a series of puzzles, simulations, and many, many colorful squares and triangles. This project, created by Vi Hart and Nicky Case, is short, but very insightful and entertaining. Make sure to check it out by clicking the image below.

Audio Illusions

The chances are you have already seen the hundreds of optical illusions we have collected for you on Puzzle Prime, but have you ever encountered any audio illusions? The YouTube channel AsapSCIENCE has created a short video in which they present and explain some of the most famous audio illusions, such as the McGurk effect and the Tritone paradox. Watch their video below and see if you can trust your ears.

The Coolest Crossword of All Time

In 1996, just a day before the election of the 40th President of US, the New York Times published a curious crossword. In the 8th row, the solver should discover a phrase – the “lead story of tomorrow’s newspaper”. More precisely – the name of the future President of the country appears there. But how could New York Times know whether it was going to be Clinton or Bob Dole?


1. “___ your name” (Mamas and Papas lyric)
6. Fell behind slightly
15. Euripides tragedy
16. Free
17. Forecast
19. Be bedridden
20. Journalist Stewart
21. Rosetta ???
22. 1960s espionage series
24. ___ Perigion
25. Qulting party
26. “Drying out” program
28. Umpire’s call
30. Tease
34. Tease
36. Standard
38. “The Tell-Tale Heart” writer
39. Lead story in tomorrow’s newspaper, with 43A
43. See 39A
45. Gold: Prefix
46. ___ Lee cakes
48. Bobble the ball
49. Spanish aunts
51. Obi
53. Bravery
57. Small island
59. Daddies
61. Theda of 1917’s “Cleopatra”
62. Employee motivator
65. Otherworldly
67. Treasure hunter’s aid
68. Title for 39A next year
71. Exclusion from social events
72. Fab Four name
73. They may get tied up in knots
74. Begin, as a maze


1. Disable
2. Cherry-colored
3. Newspaperman Ochs
4. Easel part
5. Actress Turner
6. Ropes, as dogies
7. Place to put your feet up
8. Underskirt
9. First of three-in-a-row
10. Lower in public estimation
11. Onetime bowling alley employee
12. Threesome
13. English prince’s school
14. ’60s TV talk-show host Joe
18. Superannuated
23. Sewing shop purchase
25. TV’s Uncle Miltie
27. Short writings
29. Opponent
31. Likely
32. Actress Caldwell
33. End of the English alphabet
35. Trumpet
37. Ex-host Griffin
39. Black Halloween animal
40. French 101 word
41. Provider of support, for short
42. Much debated political inits
44. Sourpuss
47. Malign
50. “La Nausee” novelist
52. Sheiks’ cliques
54. Bemoan
55. Popsicle color
56. Bird of prey
58. 10 on a scale of 1 to 10
60. Family girl
62. Famous ___
63. Something to make on one’s birthday
64. Regarding
65. Quite a story
66. Dublin’s land
69. ___ Victor
70. Hullabaloo

The answer is simple, yet very impressive. The crossword’s author, the mathematics professor Jeremiah Farrell, created the puzzle so that it could be solved in two different ways, revealing either “Clinton Elected” or “Bob Dole Elected” in the middle row. Many of the newspaper’s readers didn’t realize the prank and assumed New York Times was displaying a bias towards one of the candidates. They started sending lots of angry letters and calling the editor, complaining about arguably the coolest crossword of all time.


Which was your favorite part of the Mathematics you learned back in high-school? Not sure about you, but we definitely loved the construction problems, where we had to draw some shape, using just a straightedge and a compass. Even though we haven’t solved such problems for many years, we got very excited to discover the amazing game Euclidea, designed by the guys from HORIS International Ltd. If the description below seems intriguing to you, make sure to visit the game’s website and test your skills by clicking the banner below.

OK GO – “The Writing’s On the Wall”

How much effort and innovation can a band put into producing their music videos? When it comes to the American rock-band OK GO, the answer is A LOT. Becoming a notable YouTube presence around 2010 with their famous “Treadmill Dance”, OK GO keep pushing the boundaries of creativity in each consecutive video they make. Check out this amazing optical illusion video by these so talented guys, and if you enjoy it, make sure to see their other projects as well. Truly brilliant!

Leonid Mochalov

Leonid Mochalov is a Russian puzzle writer and inventor, who has published several brain teaser books and patented numerous mechanical puzzle toys. We decided to invite him for an interview at Puzzle Prime and learn about his passions, habits, and views on Pokemon GO. You can see all of Leonid’s puzzles on his personal website.


Q. Hello Leonid. When did you discover your passion about puzzles? Was it influenced somehow by your education or occupation at that time?

A. It happened during my school years. I published my first puzzle when I was 13 years old. Education and occupation had nothing to do with it.

Q. What drives you to make all these puzzles?

A. Ambitions. When I was young I decided to become a famous puzzle creator, such as the great Henry Dudeney or Sam Loyd.

Q. You have invented many mechanical puzzles. Do you ask professionals to build them based on your concepts, or you do it yourself?

A. I post the blueprints of my puzzles and their descriptions on my website for free. After that, various puzzle collectors and companies make physical copies of them.

Q. Designing 3-dimensional puzzles seems incredibly challenging. Can you describe how the process of creating one goes?

A. I have a very well developed 3D imagination. First, I think of a geometric object of an unusual shape, and divide it into smaller pieces. Then the pieces are glued together and the brute-force method comes. Another possible approach is to come up with a single piece which locks the entire structure.

Q. Which is your favorite physical puzzle of all time?

A. My favorite puzzle is the “Chess Cube”.

Q. And which is your favorite puzzle you have invented?

A. The “Pyramid” – it is an analogue of the “Soma Cube”.

By the way, despite the abundance of mechanical puzzles in stores, the real (classical) ones are not more than 100. These two can be classified as such.

Q. Do you like more mechanical puzzles or pen and paper problems?

A. I lost my interest in pen and paper problems in the early 90s, and then I focused my interest on mechanical puzzles. I believe a good mechanical puzzle is worth a lot more than any pen and paper problem. 

Q. Where can people buy your puzzles from?

A. Many of my mechanical puzzles are sold in specialized web-stores. 

Q. It looks like the new generations do not appreciate problem-solving as much. Do you think there is still appreciation for puzzles nowadays?

A. Not that much in our country. The pick of the interest was in the last quarter of 20th century. After that computerization and shooting games came into play. The contemporary epidemic is “Tank Wars” and “Pokemon Go”.

Q. Do you keep in touch with other inventors, maybe collaborate on projects together?

A. Not quite, I tend to work mostly alone.

Q. Some people find listening to music during work quite helpful. What about you – do you listen to anything while designing your puzzles?

A. I don’t listen to music when I work, because I find it distracting. However, I listen to disco style songs of 60-70s in my spare time.

Q. You seem a bit old-school. Do you work often on computer, play video games, watch movies? What are your hobbies overall?

A. I do non-professional photo and video shooting, so sometimes it is necessary to work with materials on my computer. Other activities I practice are following news, downloading movies and programs, watching Sci-Fi’s and thrillers. I don’t play video games however. I also used to play card games like “Preference” before retirement.

Q. You look in good shape, we know you enjoy fishing. Do you do any other sports?

A. I don’t actually. I used to jog, but then gave it up.

Q. Do you think puzzle solving is beneficial for people, especially younger children and teenagers?

A. It is very necessary for development of young generations. Puzzle solving is educational and distracts from drugs and alcohol.

Q. Tell us a funny science joke or an anecdote.

A. Something I find amusing is related to Einstein’s had 2 cats. It is common in the West people to have an opening in the door for their pets. However, Einstein had two openings – one for the big cat and the other for the small cat. It wouldn’t be like that in case of a normal person since the small cat can go through the big hole too.

Q. Thank you for the interview Leonid, wish you all the best in your endeavors.

A. Thank you for inviting me too.