Does anybody remember Klotski? It was a popular computer game released by Microsoft during the Windows 3.1 era, loosely based on a number of old logic puzzles consisting of wooden blocks. Object of the game is to manipulate the pieces by sliding them around one at a time so as to help the red piece escape the enclosure and reach the goal. Some of the more advanced puzzles also have additional obstacles within the perimeter area outside of the enclosure. One of the puzzles in the first few levels is a direct copy of an old Japanese puzzle "Daughter In The Box" （箱入り娘）.

Klotski Version:


Traditional Japanese Version:


Optimal solution:
http://www.youtube.com/watch?v=wE5KFf5QotI

Though the stage 1- levels are not too hard, try this one (Level 3-8, Sunshine) on for size. It is the last and hardest level of the game:For the record, try as I might, as a teenager in the 90s, I was never able to move the red piece more than a couple of notches, though I did solve most all of the level 1 and level 2 puzzles, and I think the first couple stages in level 3. I haven't really given it much thought or played much with it since long before my twistypuzzle obsession started up in 2007. My spatial reasoning may have increased slightly since then, from all the puzzle solving I have done.

Anyway, somebody uploaded a full solve video on youtube about a year ago, if you want to check that out:
Sunshine Phase 1: http://www.youtube.com/watch?v=EciK4qlqFCA
Sunshine Phase 2 Part 1: http://www.youtube.com/watch?v=vpt5RDnYQ_M
Sunshine Phase 2 Part 2: http://www.youtube.com/watch?v=miHRusKbe2g

http://www.bricks-game.de

Have fun.

HOLY CRAP! I have been looking for this game for FOREVER! Thanks!

Jared's link doesn't work for me. Anyway, I tried searching "klotski forget-me-not" in google, and it came up with a pet crematorium.

http://www.bricks-game.de/indexuk.html

Maybe that one does?

The game doesn't have Sunshine, I should point out, but it certainly does get just as difficult.

Thanks Jared for the link
I don't wee why the link wouldn't work. They have a DOS version and a Windows version. The 32-bit windows port is here,
http://www.bricks-game.de/winbricks/bricks1.zip
and surprisingly enough, dinosaurish as the app looks, it still runs fine on Vista 64 which is far more than I can say for the original Klotski (16-bit apps don't work on 64 bit Windows).

Sadly, they won't just give you Bricks II, III, IV and so on until you've sent in your save file proving that you are worthy by beating all 48 levels in the previous edition Some of the levels in the first Bricks are direct copies of the Windows Klotski puzzles, but many are also brand-spanking new.

PS- The sunshine level can be found here (not compatible with 64 bit):
http://www.bricks-game.de/html/downloadmap.html
http://www.bricks-game.de/zip/sunshine.zip

Having made it all the way to Bricks IV, I can safely say that this is completely justified. They get REALLY REALLY HARD.

Most complex ever?! Well, certainly not most complex possible...

For all you math/computer people out there on this forum, sliding block puzzles are PSPACE-complete! (Check out http://groups.csail.mit.edu/mac/users/b ... blocks.pdf for a little blurb about why, or google them, of course.) For everyone else who have no idea what PSPACE means, it's an even harder class of problems then the considerably more famous NP.

Here's an alternate download link:
http://ajisabaki.com/palace/math/klotski/klotski.zip

You are welcome.

Okay, I downloaded all the custom and past competition levels, and may I go on record by saying that some of those stages are insane. They're not all simple manipulation, like in some levels there are blocks that can only slide either horizontal vertical directions (there was another simpler game called "cars" that used this mechanic. Those pieces are okay. But there are certain sets of disconnected blocks that move in tandem with one another, holes that delete pieces off the board (even your "goal" pieces), magnets that attract and repel each other (once attracting magnets are stuck together, they are permanently stuck in that shape), sticky glue tiles that pieces get permanently stuck upon contact, water tiles, floaty "wieghtless" bricks, frictionless ice tiles, in which a piece slides across until hitting a barrier, booby traps that lock up the grid in a Minesweeper type fashion, "keys" which disarm said booby traps, etc etc etc.

I liked just the simple "sane" block manipulation puzzles in which tiles merely slide around everywhere, and it would be technically possible at any stage to rearrange the blocks back into the starting config. Even some of the custom user-created levels which only use the "classic" elements seem beyond complicated. All of these "special" blocks, esp the ones which have permanent effects on the board, are more than my brain can grasp!

I'll play with some of them, but the special tiles/blocks are just too confusing
For "PSpace complete", are you referring to merely finding minimum optimal solutions, or just finding any solution, regardless of how many moves? How about just the standard block puzzles without the funky combinatronic/special rules/permanent effect tiles?

It's PSPACE-complete to find any solution for an "ordinary" sliding-block puzzle, without any special rules.