I was looking recently to see if Nikoli had put out any more iOS versions of their puzzles; they hadn’t, but I saw several apps from Conceptis, and I have a lot of respect for them as well. So I downloaded a bunch of those and started giving them a try. Which I’m very glad I did; if you’re a puzzle person, I highly recommend them! It was interesting seeing how they grappled with user interface issues, though.

I started with Slitherlink, because that’s my single favorite puzzle type. Good app, very good puzzles, the hard ones really aren’t joking around. Right from the start, though, the interface is slightly unexpected (I wasn’t the only person surprised by it, Miranda was as well): sometimes tapping on a line cycles between filled in / crossed out / blank, but sometimes it doesn’t. After a bit of experimentation: if the line is next to a vertex with either two lines into it already or with at least three blank spaces, then tapping on the line goes straight to crossed out. Which, on the one hand, makes sense—the line can’t ever be filled in in that situation. But, on the other hand, it both makes the reaction of the game to your taps a little unpredictable at the start; and why stop there with the filling in, why not take numbers into account as well?

And then I noticed a setting which goes even farther in that direction: if that setting is turned on, the game will proactively cross out lines where the normal mode would not allow you to draw a line. (And those crosses will cascade if appropriate, too.) Which makes me wonder: what’s the limit of tool assist modes in puzzles, given that the goal of the puzzle is for the player to feel like they’re figuring something out? Conceptis made an interesting choice here: my guess is that, if they took numbers into account as well, it would feel like the game was doing a bit too much work for you, at least on the easy and medium difficulty puzzles.

Having said that, I really like having the tool exist as implemented: it makes the medium puzzles pleasantly soothing, and the hard puzzles are still quite difficult (taking 25 minutes on a large one is pretty normal), with me feeling that I’m spending time thinking instead of doing grunt work. In fact, I’d like a little more tool assistance there—I still spend a fair amount of time filling in stuff that’s routine, I’d like to move beyond that.

I’ve wondered for a while what a version of Slitherlink would be like that let you prove theorems and then that let you apply them, or even applied them automatically for you. My guess is that it wouldn’t be super fun, but who knows; and maybe it would be fun if the puzzles got hard / large enough? Dunno, maybe I’ll give it a try the next time I feel like taking on a decent sized programming project.


Of course, Slitherlink isn’t the only Conceptis game I tried. Their implementations of Nurikabe and Hashi are quite solid as well, albeit without such interface subtleties. More interesting from an interface point of view are their “Pix” games: Pic-a-Pix, Link-a-Pix, and Fill-a-Pix. These all have you moving around a grid manipulating squares; and, in all three games, instead of just being able to tap on a square to do something to it (basically, mark it as filled in / known blank / unknown), you slide a cursor around and then tap anywhere on the screen to change the state of whatever square is under the cursor.

This was super annoying at first. (And again, not just me: Liesl felt the same way.) But I got a lot more sympathetic to it after a little while: at the same time, I was playing Paint it Back, which has the same rules as Pic-a-Pix or Picross. And it was a charming game, but the puzzles were all straightforward; maybe the game wasn’t trying very hard, but maybe that was because the game wasn’t willing to show me a puzzle larger than 20×20 on a single screen?

I haven’t gone through the larger Pic-a-Pix puzzles in game yet, but even the free pack goes up to 50×35; taking a look at that one, it definitely would not work with direct tapping. So if the tradeoff is between good puzzles and a direct manipulation interface, I’ll take the former all the time. Though, thinking back, Picross DS didn’t force that choice on me; I guess the D-pad really helped there? Looking at the puzzles, though, that game only went up to 25×20, which I think is probably manageable with direct manipulation on an iPad, I guess the Paint it Back folks just didn’t do a good job of puzzle design.

The other point of comparison here is Piczle Lines, which has the same rules as Link-a-Pix. That one managed fine with direct manipulation; yes, you had to shrink and enlarge the screen some of the time, but that was okay. So maybe the Conceptis folks should have given that as an option? That might not work for Pic-a-Pix/Picross, though, because that puzzle type requires more global information.

Anyways: if you don’t see me blogging much these days, you can blame it on the fact that these games are so good and so easy to pick up in random moments of my time. (Some interesting different modes, too—I think I might end up liking the color version of Pic-a-Pix more than the standard version.) I suspect I’m going to have spent quite a lot of money on puzzle packs by the time this is all said and done; and it will totally have been worth it.

Post Revisions: