Kudosu: A Deceptively Simple Number Puzzle Game - Free Online Demo Now Available

[eZanmoto]

Hello Exilian! As promised, Clever Kiwi Games is thrilled to announce the launch of our second title, Kudosu, coming this Friday! For the impatient, the demo is available >here<

Kudosu is number puzzle game with simple rules and a lot of depth. Relying on your basic instincts can have dire ramifications in Kudosu, as the obvious move is often ill-advised. An ability to deduce patterns and see into the future are highly recommended.

The influence of Sudoku in the creation of Kudosu becomes apparent when one finds out that the rules fit in a single tweet. However, these simple rules hide a depth that can only be appreciated through experience.  You will begin to see patterns. They will often be incorrect. You may notice similarities between levels. They're actually very different.

Clever Kiwi Games is a new indie game company that hopes to appeal to a mass casual audience by creating small games with cunning mechanics that provide a lot of replay value, and also reach out to an audience of both older gamers and female gamers that are typically neglected by modern mobile gaming. Find out more at http://cleverkiwigames.com.

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EDIT: urls fixed

[Glaurung]

This looks interesting, and I was hoping to give it a try. Unfortunately, there's no url in the "demo is available >here<" link in your post. Then I went to your Twitter page, and found a link to your demo page there, so I went to the demo page. That showed me your logo (nice bespectacled kiwi bird) and the text "Loading audio", but no actual demos. Is my browser (Firefox) hiding something from me, or do I need to come back later?

[eZanmoto]

Oh no, I always make the silliest mistakes, thanks very much Glaurung for letting me know! The audio doesn't seem to work with Firefox and is preventing the game from loading, so I've removed it for now until I implement a proper fix. Thanks again, I hope you enjoy the game!

[Jubal]

Well, the two four-square puzzles available were pretty simple but then they kind of would be! It's a really nice concept though, looking forward to having some more challenging ones to have a crack at

Will the puzzles in the real thing be pre-set or procedurally generated somehow?

[Glaurung]

Thanks for fixing the audio - I've now had a go at the two demos. Definitely interesting, and quite subtle - even a 2x2 grid needs some thought before starting.

[eZanmoto]

Thanks Jubal and Glaurung! To answer your question Jubal, they're actually both in a way There are 50 puzzles featured in the main game - these were randomly generated in a way that eliminated duplication in the puzzles (such as symmetries and rotations), and then filtered by hand based on how challenging they were, how "interesting" the solution was, and so on. In the full app, completing all featured puzzles will unlock "Infinite Mode", which will be purely randomly-generated and will also contain puzzles that are much easier than the featured puzzles, but mainly puzzles that are much harder. Regardless, all puzzles will be solvable (though I've doubted myself sometimes and actually had to look up solutions )

[Clockwork]

I too played the demo, I'll throw the link and a recommendation around

[eZanmoto]

Thanks a million Clockwork, that'd be much appreciated 

[eZanmoto]

Today's puzzles have been added to the demo, check them out!

[Glaurung]

Thanks, I have. For no obvious reason I was expecting they would always be square.

I'm now getting curious about the maths and logic of these puzzles. It feels as if there ought to be a fairly simple test to determine whether a grid of numbers is a valid Kudosu puzzle - I've come up with a necessary condition, but I suspect it's not sufficient. I'm also trying to work out whether there's a reliable algorithm for selecting the cells to clear.

I'm also curious about how your puzzle generator works. The only approach I can think is a "reverse solution" - the generator picks cells in the grid (randomly?) and adds 1 to each cell in the same row and column.

One other, rather different, thought: "sudoku" means "single number" in Japanese - does "kudosu" mean anything, and if so, what?

[Jubal]

Another interesting point, as exemplified by puzzle 4 - it's possible to have multiple paths to completion in a kusodu puzzle, though I'm not yet sure how complex the differences between paths can be.

[eZanmoto]

Interesting points!

@Glaurung I haven't actually considered or implemented a validator, and off the top of my head I can't think of an algorithm for solving the puzzles other than to brute force them, which I suppose is a nice property if it holds! You're spot on with your guess for how the generator works As for "Kudosu", it's simply a reversal of the characters in Sudoku, as you may have guessed Nice tidbit on the meaning of Sudoku though!

@Jubal As far as I have determined (i.e. not proven) there is actually only one combination of "taps" that solves a given puzzle, but the order they're pressed in doesn't matter. Knowing that the order doesn't matter can reduce the difficulty of the puzzles a bit, but I think that larger grids and "deeper" puzzles still make the puzzles sufficiently hard

[Jubal]

Yes, OK - that intuitively makes sense given that (thinking aloud as I'm typing here) the reductions are always by a constant number and so have to effectively take the form of multiple overlapping "layers" of crosses emanating from particular points. Essentially the puzzle is to find where all of the crossover points are, meaning that there can be only one soluttion; the crosspoints can't be in multiple place. I suspect it's provable in more formal terms too. Hm. Need some mathematicians on this, I'm just a mere historian!

Re Glaurung's point - it may be worth asking someone who knows Japanese if the word you've put together does inadvertently translate as anything, to avoid the possibility of launching it and then discovering that it did mean something entirely unintentional!

[Glaurung]

Re Glaurung's point - it may be worth asking someone who knows Japanese if the word you've put together does inadvertently translate as anything, to avoid the possibility of launching it and then discovering that it did mean something entirely unintentional!

Yes, that's what I was trying to say. I'm thinking of Rolls Royce, who wondered why their Silver Mist model didn't sell well in Germany, only to discover that "Mist" means poison in German!

Meanwhile, I checked in Google Translate, for what it's worth. "kudosu" seems to mean several different things in Japanese, depending on where spaces are put. Without spaces it gave me "kudos", while "kudo su" came back as "to verbosity" (!) and "ku do su" as "to ward soil".

[Jubal]

Further thoughts on provable properties of the game - I think that if my thesis above (that the aim is to click on all the crosspoints but the order doesn't matter) is true, it also should hold true that it is impossible to make an incorrect move (that is permissible by the empty-square-lock rule) and still win the game. I certainly can't think of a scenario in which one could make a set of other moves to "correct" an incorrect one.

Thought on game design - it would be nice if the game told you when no more moves were possible and you've "lost". I mean it should be obvious, but I'm not sure it always will be with more complex puzzles.