Parity, a numbers puzzle game

[robinhouston]

I like this! I think I’d enjoy it more if there were a back button, to undo the last move, as well as the reset button to start again from the beginning. It’s frustrating to have to start again because of a single mistake.

[abejfehr]

I thought about adding that, but it makes the game a bit too simple.

[mightybyte]

As others have mentioned, it does seem fairly easy once you get a feel for the game mechanics. I might suggest that you have each level include a max number that each tile has to have for a correct solution. I found myself trying to get the lowest number, but I almost get everything to say 5, but messed up and missed one tile that had to get bumped to 6, it was then easy to just make one more pass and set everything to 6. If I had to restart to get the 5 I think it might be a slight increase to the difficulty.

[Chinjut]

Hm... You're saying it can be possible to solve two different ways with two different numbers?

Suppose the corners and the center are black and the other squares are white. Then every two moves in a row adds one to black and one to white. So an even length sequence keeps the difference between the black sum and the white sum the same. In the end, with all values set to X, this difference equals 5X - 4X = X.

Thus, for an even-length game, we know from the start what X must be: the difference between the black and white sums.

This means there's no room for a wrong move. Any solution has a prescribed number of times to hit each tile. (FWIW, the total number of moves will be 9X - the starting sum = 9(B - W) - (B + W) = 8B - 10W)

So far, we've assumed we'll be playing an even-length game. Might we actually be playing an odd-length game? Sure. In that case, we also know from the start what X should be (since it amounts to making one move, adding 1 to the color not started on, and then playing an even-length game).

Is there an easy way to see from the start whether we play an even- or odd-length game? Is it possible that both are allowed for a given board? It's not yet clear to me. I'll reply with updates. But at any rate, there are at most two different values you can solve with, one for even-length solutions and another for odd-length solutions (and these two values will be next to each other).

[This is all for the version of the game in the early levels. I see from other comments that the game changes at level 51, which I haven't played to yet. I also see that "black" and "white" start actually being used in the game at that point, making this explanation potential confusing.]

[hoopism]

I agree with this... seemed tough till I realized how forgiving it was. I gave up after few minutes... maybe later levels introduce this complexity?

[cokernel]

Interesting game. There's a minor typo in the instructions: 'the a' should be either 'the' or 'a'.

[pbhjpbhj]

Needs a one-line description on the game page - "move the focus with cursor, or drag, to change the focussed number - make all numbers equal to complete the board" (that's my 30s attempt at an understandable description). I jumped in an missed the rules and then wasn't exactly sure of the mechanism/aim and there were no rules on the page and I couldn't get back to the splash screen without removing the cookie (the setting of which technically breaches EU law - https://ico.org.uk/for-organisations/guide-to-pecr/cookies/ is about the UK rendering of the "Cookie law").

[abejfehr]

I'll definitely read over the law and take care of that issue. Thanks so much for bringing that up! Instead of having a one-line description on the game's page I'm going to make a visual cue for the first level as well as instruction that shows there

[volent]

I don't know if it's a good feature or not but I enjoyed being able to finish the game using the solutions found in /parity/story.json.

Would not be a good feature if you want to create some sort of leaderboard.

[tom-lord]

Nice find! For anyone else wondering, you can see the main game source in scripts/modules/Story.js - which includes the line:

    $.getJSON('story.json', function(data) {

[ap22213]

I skipped ahead and just started playing the game, and the mechanics weren't clear at all.

I know that I should have read through the instructions, but I'm sure there are a lot of people like me who just want to jump in and play.

[Igglyboo]

Really? I skipped the rules as well and understood the mechanics after about 10 seconds of playing.

[fredley]

Great game, but it took 50 levels to get more difficult. Suggest bringing in the new rules earlier on, I was getting pretty bored by about level 30 when I'd worked it out well enough to zoom through the levels.

[caractacus]

There was a typo on the homepage - 'a the' or 'the a' or something - but now I've played five levels I can't get back to the homepage to find it.

[evanb]

This is great. It would be good to let people look back at their previously played levels so they could check the understanding they develop later in the game.

[mzs]

This is very nice, thank you. I was hoping that when I click on the number on the lower left it would let me get to harder higher levels.

[jokoon]

this always baffles me: how do people invent those simple games ? Is it about game theory or game design ? Or just simplicity ?

[Extigy]

Not as pretty as OPs but I made this little game: http://extigy.github.io/primes/

I didn't really think about game theory or anything. I just had an idea and wondered how it would play.

[lorenzo20002]

It's nice, but easy too. Once you decide the last number you have to move accordingly

[mkagenius]

That's the thing with problem creation, it becomes either too easy or too difficult. (Not saying that this one is way too easy)

I recollect someone suggesting letting bots(AI) play a number of variations of the game first and then use the outcome to ascertain the difficulty - may be an overkill for a fun game like this?

[snw]

after level 50 there are black & white tiles that increase/decrese the value when you step on them.

Not so easy anymore

[jastanton]

Prepare for app store copy cats in 3... 2...

[e28eta]

This game mechanic reminds me a lot of Bicolor, an existing iOS game.

[bryceadams]

This is super cool.

[CaptainClueless]

Make all numbers equal.

https://github.com/abejfehr/parity

[Kiro]

What do you mean?