I had the app installed way back when, and it was fun. I reached my limit around 60-90 step solutions. The numbers are a little deceiving: in many cases there are sequences of moves 3, 4, or 5 (or more?) long where only one move is possible, and therefore in a sense they qualify as only one decision as a unit, even if they are multiple moves. I think this same aspect is sometimes true of Rush Hour, but less so.As far as I know it was iOS-only. I think the author created the puzzle as a phd paper, and once I found the paper itself online. It was interesting reading.It should be possible today to vibe code the mechanics as a web app, right?

Does anyone know if a version of this is available for Android? I&#x27;ve had no luck searching.It also seems like something that would be great as part of Simon Tatham&#x27;s puzzle collection: <a href="https:&#x2F;&#x2F;www.chiark.greenend.org.uk&#x2F;~sgtatham&#x2F;puzzles&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.chiark.greenend.org.uk&#x2F;~sgtatham&#x2F;puzzles&#x2F;</a> &#x2F; <a href="https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=name.boyle.chris.sgtpuzzles">https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=name.boyle.chr...</a>

Since the author seems interested in the maximum number of moves required to solve the puzzle, a similar puzzle called Subway Shuffle far outdoes Rush Hour. For example, puzzle 100 involves 9 pieces on a 10-spot grid, but requires (as far as is known, maybe the solution isn&#x27;t optimal?) 589 steps to solve. <a href="https:&#x2F;&#x2F;www.cs.brandeis.edu&#x2F;~storer&#x2F;JimPuzzles&#x2F;ZPAGES&#x2F;zzzSubwayShuffle.html" rel="nofollow">https:&#x2F;&#x2F;www.cs.brandeis.edu&#x2F;~storer&#x2F;JimPuzzles&#x2F;ZPAGES&#x2F;zzzSub...</a>

It turns out that Rush Hour becomes much harder if we shrink the cars from size 2x1 to size 1x1, while maintaining their direction to be either horizontal or vertical [1].
While the hardest 6x6 Rush Hour puzzle takes 51 moves, the hardest Unit Rush Hour puzzle takes a whopping 732 moves [2].[1] <a href="https:&#x2F;&#x2F;tromp.github.io&#x2F;orimaze.html" rel="nofollow">https:&#x2F;&#x2F;tromp.github.io&#x2F;orimaze.html</a>[2] <a href="https:&#x2F;&#x2F;tromp.github.io&#x2F;rh.ps" rel="nofollow">https:&#x2F;&#x2F;tromp.github.io&#x2F;rh.ps</a>

Great article, very impressive to solve the entire game, rather than just individual puzzles.PS: Good chance that if you&#x27;re reading these comments that you will appreciate this video by 2swap, visualising solutions to Rush Hour in 3D: <a href="https:&#x2F;&#x2F;youtu.be&#x2F;YGLNyHd2w10?si=fGFqzEbmV3utbA0O" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;YGLNyHd2w10?si=fGFqzEbmV3utbA0O</a>

A little shameless plug:Ive just released a game built around this project on play store - <a href="https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=com.noobgiraffe.unblock">https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=com.noobgiraff...</a>Has 4x4, 5x5 and 6x6 puzzles. Generating 7x7 puzzles is long process and i think i may have to do it on cloud, but am planning to release them soon.

Fun article.The Rush Hour puzzle is quite fun when viewed as a planning problem. In standard PDDL the model becomes very messy. I like the 
extensions proposed in <a href="https:&#x2F;&#x2F;arxiv.org&#x2F;abs&#x2F;2412.06312v1" rel="nofollow">https:&#x2F;&#x2F;arxiv.org&#x2F;abs&#x2F;2412.06312v1</a> that makes the model intuitive.

I played this a lot as a kid. There are so many &quot;levels&quot; - it&#x27;s fantastic and addictive - but like in a good way where you&#x27;re using your brain.

Thanks for the article, perfect timing. Was stuck on a secret Santa gift for the brother in law. Rush hour is perfect!