BoppreH 2 days ago

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.

---

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/

  • bogdanoff_2 2 days ago

    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 days ago

      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.

james_marks 2 days ago

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

  • bogdanoff_2 a day ago

    I like your puzzle game. Yeah, it did take me a bit to understand initially. I wonder, do you generate the daily levels automatically?

    • james_marks a day ago

      Glad you enjoyed it. Yeah, the daily levels are algorithmic with an RNG seeded with the date.

      Took ages to find an algorithm that produces mostly interesting puzzles in the goldilocks difficulty zone.

mmis1000 a day ago

The game is quite fun. But it seems the difficulty ramp quite late? It's not very difficult to get the answer with least step by solve the side first until about last 20 levels.

Also, the game does give you a hint about how to bruteforce the level if you only have one square left. Good job.

  • bogdanoff_2 12 hours ago

    Good point. I definitely need to work on the progression.

jy14898 2 days ago

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

snowfield 2 days ago

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

stephenlf 2 days ago

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

stephenlf 2 days ago

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

  • bogdanoff_2 2 days ago

    That makes sense. I think what I'm gonna try is hiding it until the level is solved at least once.

intalentive 2 days ago

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.

atum47 2 days ago

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.

  • mkl 2 days ago

    Worked fine for me on Firefox on Galaxy Note 20. I've never run into single finger back gestures that can start anywhere - seems like that would break almost everything that involves dragging.

  • bogdanoff_2 2 days ago

    Interesting. I don't get that on my android phone. What model and browser are you using?

martin_balsam 2 days ago

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

kinduff 2 days ago

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

zem 2 days ago

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

slig 2 days ago

Great game, thanks for sharing. Would love to have a daily level.

  • bogdanoff_2 a day ago

    Yeah, it's my plan to implement daily levels, as well as weekly levels.

    I was thinking of making weekly levels be very big (like 12x12) where I don't know what the par is myself, and have it be a challenge to see who in the community can figure out a way to get the lowest number of moves.

    And daily levels would probably be more similar to the regular levels.

sd9 2 days ago

This was incredibly easy and then it suddenly got incredibly hard

wilsonnb3 2 days ago

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

  • bogdanoff_2 2 days ago

    Thanks! I'm glad you enjoyed it!

berkaycit 2 days ago

It’s amazing. It inspired some new ideas.

mikewarot 2 days ago

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

  • mmis1000 a day ago

    It actually have a dedicated answer to solve just 1 square though. But it's not the most optimized way to do the puzzle.

  • bogdanoff_2 2 days ago

    wait, did you actually do the whole 120 levels in one sitting? Wow. How long did it take you?

bogdanoff_2 2 days ago

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

  • penwielder 2 days ago

    (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.

    • bogdanoff_2 12 hours ago

      So what is your solution, I'm curious.

      Regarding the number of solvable boards. It is actually possible to calculate the exact number. The solvable boards correspond to the image of the matrix of moves. It will be a vector (sub)space over Z/2Z, so it will always be a power of 2, and its size will be determined by the rank of the matrix. For example for 5x5, there are 2^22 valid boards.

      And regarding the number of solutions to a given board, (assuming you ignore the order of moves, because it doesn't matter) it will always be the exact same number, and in the case of 5x5 it will be 2^8. 8 is the nullity of the matrix of moves.

      Note that 22+8=30, which is 44+33+22+11, which is the number of possible moves.

  • NatKarmios 2 days ago

    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.

    • bogdanoff_2 a day ago

      That's pretty cool. It reminds me of writing peep-hole patterns for an optimizing compiler.

stevenalowe a day ago

ASMR FTW

Well done!

  • bogdanoff_2 7 hours ago

    All the sound is purely from the vibration of your phone!

Retr0id 2 days ago

Level 60 is a fun one

  • anigbrowl 2 days ago

    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 days ago

    Ah, yes, the single-pixel level.

  • senfiaj 2 days ago

    yeah, eventually figured out how to do in 5 moves

fsckboy 2 days ago

i have a strong quibble about calling this XOR. XOR takes two arguments and one of the arguments here is implicit. The game inverts the square colors, which XORing with "1" will do, but it's not defined whether white or black is 1, it just inverts white and black.

  • bogdanoff_2 a day ago

    The way I thought of it was 0=white 1=black. I used the term XOR when posting on hacker news because I thought people here might have an intuition about the kind of patterns it could form in 2D

    • fsckboy 3 hours ago

      I have the intuition, I understood what you meant. but I still think it's an error.