Show HN: Unflip – a puzzle game about XOR patterns of squares

Very nice and satisfying, but I would suggest ramping up the difficulty a little faster. I got until lvl 15 by just flipping the obvious areas, taking no more than 2 seconds. It's otherwise very cool and minimalist.

Edit: limiting it to square flips was a great idea. There are just enough moves to make the answer non-obvious (after lvl 15), but not so many possible moves that you get overwhelmed.

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Edit 2: I just remembered I made a similar "game"[1], where you select columns to XOR with other columns and try to reach the target pattern. Use the scroll wheel and shift+wheel to change the pattern and size.

That was actually part of a real research project in optimizing circuits for computing binary finite fields, where the "game" was a sandbox to try different algorithms. The best algorithm was actually found by someone playing in this sandbox and coming up with an efficient strategy.

[1] https://boppreh.com/source/playreduce/

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bogdanoff_2 4 hours ago | parent [-]

Thanks! And yeah, I've gotten the suggestion to ramp up difficulty faster from a few people.

Although interestingly some other people in the comments here say they liked how the progression goes.

And that's an interesting little game you made.

And I spent quite some time creating an algorithm and solver to find the par for Unflip. I'm planning to release a blog post about it soon

	▲	riffraff 2 hours ago \| parent [-]
		I think if you make the par visible in the "result screen" and add a "try again" option to "next" this could make it more interesting without the need to ramp up difficulty. I think I solved a few cases with a bunch of random shifts, for example, and may have switched to thinking mode if I was faced with that.

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james_marks 6 hours ago | parent | prev | next [-]

Really nice concept and super clean execution. Wish I’d had 1/2 this restraint on adding complexity when I made my own tile-based puzzle game[0]

[0] https://www.hidden-mirrors.com

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jy14898 8 hours ago | parent | prev | next [-]

Stopped at 74 but managed to par all before that somehow. Didn't really do any problem solving/deep thinking about it, just clicking what felt right

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snowfield 8 hours ago | parent | prev | next [-]

Played until 27. All the levels were pretty easy, 15-30 seconds per level. Mainly because of the "par" feature

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atum47 6 hours ago | parent | prev | next [-]

Android gestures need to be prevented in order for the game to work on mobile (drag finger from right to left go back). Nice game thought.

	▲	bogdanoff_2 4 hours ago \| parent [-]
		Interesting. I don't get that on my android phone. What model and browser are you using?

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kinduff 5 hours ago | parent | prev | next [-]

Did I just get flipped in level 13? I really like it, the level progression feels good. Very nice execution.

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intalentive 7 hours ago | parent | prev | next [-]

I like it. Played a bunch of levels. I could feel my brain learning new patterns (like the card game Set). There are a handful of really useful primitives.

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stephenlf 9 hours ago | parent | prev | next [-]

Love it. The “par” value is a huge hint. You might consider hiding it

	▲	bogdanoff_2 4 hours ago \| parent [-]
		That makes sense. I think what I'm gonna try is hiding it until the level is solved at least once.

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bogdanoff_2 3 hours ago | parent | prev | next [-]

If anyone wants an extra challenge: think, how would you write a solver for this?

	▲	penwielder an hour ago \| parent \| next [-]
		(If I'm trying not to spoil anything, do I even post? Maybe I can encourage someone else to have fun giving it more thought.) At least one elegant and efficient answer is within reach for many. The person who first pointed it out to me didn't need to know the relevant branch of mathematics to do so; he intuited the shape of it without the formal terminology. I'll be particularly curious to hear the pattern(s) in how many solutions there are, and/or the probability of a random board being solvable. The haptic feedback on mobile is really on point in this implementation.
	▲	NatKarmios 2 hours ago \| parent \| prev [-]
		Tangentially related, have you heard of Bombe? It's a hexagonal minesweeper where you write rules to solve every possible scenario. It even checks your rules' satisfiability via SMT.

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zem 6 hours ago | parent | prev | next [-]

I really love how the first few levels teach you about various solving elements and patterns. very well done.

	▲	bogdanoff_2 3 hours ago \| parent [-]
		Yeah, that was the idea.

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vunderba 5 hours ago | parent | prev | next [-]

Nice job. I'm reminded of the "Lights Out" game [1].

https://en.wikipedia.org/wiki/Lights_Out_(game)

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mikewarot 3 hours ago | parent | prev | next [-]

Wow... 120 levels... that was hard. I kept getting down to 1 square, and that always stumps me.

	▲	bogdanoff_2 3 hours ago \| parent [-]
		wait, did you actually do the whole 120 levels in one sitting? Wow. How long did it take you?

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martin_balsam 8 hours ago | parent | prev | next [-]

I agree the ramp up is a bit slow, but I love the concept, and the interface. I am stuck at level 26

edit: found a way to solve it in 6, but not in 4

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stephenlf 8 hours ago | parent | prev | next [-]

Level 24. I took a natural approach (pull each corner to the center) and got a rather unfortunate picture

—-

Edit: and the right answer was so obvious, too

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wilsonnb3 7 hours ago | parent | prev | next [-]

Had a lot of fun with this, great job on the concept and presentation!

	▲	bogdanoff_2 3 hours ago \| parent [-]
		Thanks! I'm glad you enjoyed it!

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lovegrenoble 8 hours ago | parent | prev | next [-]

Neumorphic knot, a puzzle about Knot patterns: https://brainteaser.top/knot/index.html

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Retr0id 5 hours ago | parent | prev [-]

Level 60 is a fun one

	▲	anigbrowl 5 hours ago \| parent \| next [-]
		Yes I got stuck there for a while. I did a few more after that but my interest waned. I did spend a lot fo time feeling ike a pixel in Conway's game of Life.
	▲	bogdanoff_2 2 hours ago \| parent \| prev [-]
		Ah, yes, the single-pixel level.