Quento: Shaking My iPhone Makes Me Sad

Example of iOS' confirm undo screenWay back in iOS 3, Apple implemented the “shake to undo” feature. This means if you’re typing, say, a text message, and you want to “undo” your text, just shake your iPhone, iPad, or iPod Touch. While it’s a cool trick, this isn’t the most usable feature that Apple has ever implemented. It’s both hidden and unintuitive. And I’ve definitely triggered it more accidentally than I have on purpose.

Quento (iTunes link) is a stylish puzzler for iOS (and Android, and Windows 8, and Chrome) that looks a lot like Letterpress except it substitutes simple math problems for word problems. It’s a good distraction for your brain, but unfortunately it’s also a good example of how not to implement a shake feature in your game. Shaking your phone resets the board, causing you to lose all your progress for that level – without any warning.

example screenshot of quento with some progress made

All that progress is one quick shake away from being gone…

Here’s how Quento works, in a nutshell: you’ve got to swipe over math problems in order to get the desired result. In the screenshot here, we’ve got to use two numbers to get to the total of 8. So 5+3=8, easy enough. You get a star for each time you solve a problem with the specified amount of numbers, and after getting all the stars, you move onto the next level.

This screenshot shows me having five of the six stars required to pass to the next level (the free version lets you play the two and three number puzzles; four and five number puzzles are an in-app purchase). Despite the big star indicating I’ve solved all the three number puzzles, shaking my phone will remove all my progress on this level. The intention is that if you get stuck on a puzzle, you can shake to get a fresh one.

Of importance here – there’s not a ton of incentive to pass to the next level. You get a new background color, and a new set of puzzles, but that’s about it. Even still, users hate losing data, and getting your progress wiped out feels a lot like that. At best it feels like backtracking, which is also no good.

Of course, it’s perfectly valid to make the player some penalty for “giving up” and wanting a new puzzle. Otherwise, a player could just keep re-rolling puzzles until they get one with an obvious answer, and that’s just lame. Apple’s implementation gives you a confirmation dialog making sure you want to undo your typing, and that would be a welcome addition here.

The thing to keep in mind is this: if you’re doing something destructive with the user’s progress (or data), make doubly sure it’s intentional. The problem with the shake gesture is that it’s really easy to do on accident. What if you’re on the bus and you hit a pothole? Or someone pegs you in the head with a Nerf dart? Or you just get mad and shake your phone because you can’t figure out how to add numbers up to 10? All valid reasons to shake. None of them should result in you losing progress.

In Words with Friends, shaking the phone causes the letters in your rack to shuffle. This is a great example of how to interpret a device shake, because it’s not a destructive action. I’ve accidentally hit the pass button more than once trying to tap “shake” instead, so I’m a fan of this one. And like with most gesture-based features, it isn’t super discoverable, but that’s okay because it’s not at all critical.


The goal behind any interface is to make it match the mental model that your users have of the system. This means that users can intuitively know how to use it based on their past experience. Shaking your phone isn’t a real common experience in the real world though, so it’s hard to come up with a universal answer to what that action should do. The closest thing is probably the Etch a Sketch, which is moderately relatable to Apple’s “shake to undo” feature.

Quento is a fun diversion to keep your math skills sharp, and the unfortunate implementation of shake to undo doesn’t kill the experience by any means. It is a good reminder though that if you’re implementing something to do with a shake, make sure it will surprise and delight users, and not resulting in another shake due to anger!

What other games (or apps for that matter) have implemented a shake gesture that you think is particularly noteworthy? Let’s discuss in the comments!


5 thoughts on “Quento: Shaking My iPhone Makes Me Sad

  1. This reminds me of an anecdote: Clubhouse Games on DS has a fun but fairly long campaign mode required to unlock all the games in free mode. At some point far in my progress, I accidentally hit the “Clear all data” button, which caused a confirmation screen to appear. The choices were “No” / “Yes”, so because they were swapped I pressed “Yes” by accident, which caused a second confirmation screen to appear. The choices this time were “Yes” / “No”, but I was so afraid to lose my progress that I immediately pressed “Yes” without realizing the buttons were swapped again. To my biggest surprise, a third confirmation screen appeared. I took a good minute before correctly answering “No” that time and thanked the game designers for those extra precautions.

    • Three confirmation screens, that is awesome. I know I’ve accidentally exited games of Madden before in a similar fashion as you describe – you hit the first exit without thinking, and immediately realizing you screwed up, just jam on some buttons and end up hitting exit again, which isn’t good.

      It’s probably also a good argument for more descriptive action buttons too. Something like “yes, delete my progress” might be more effective.

  2. Hi Mark,

    Full +1 on your UX analysis of Quento, and a big thanks for doing so. I’d love to give a little feedback.

    We also feel that shaking to reset the board is too drastic. This was a first implementation for players and especially children to get out of a situation where they feel stuck. Together with teacher’s feedback who use it in classrooms, we are doing a new implementation for the future Quento 2.0 in which a “stuck” cannot be overcome by simply getting a new board, but the more pedagogical approach of showing hints, one at a time, to help the player in seeing the solution to the current puzzle (one number or one operator at a time).

    That way, kids (or any players) will be shown how to fix it themselves, or if they continue shaking they will eventually get the answer and be able to move on. It’s always a good idea for young players to show them what the answer was instead of just giving up.

    I must say though, as a form of critique back to your analysis that I wish you had also reviewed the parts of the user experience designs that you feel we did do correctly. At @q42 we work with UX challenges every day and we take it very seriously. As such, Quento has had extensive in-house and at-home (by all our kids) testing, which lead to a many design and interaction choices that I feel you have either missed (could be of course) or that you may have focused to much on that one negative aspect – the shaking. No offense, just trying to put everything in perspective.

    So yes, the shaking – all agree there and it’s a valid point that we’ve taken seriously and have a solution for that not only we feel comfortable with, but we feel it’s backed up by teachers (my wife is a teacher too by the way) and it will be a much better non-intrusive and positive helpful feature.

    Then, on reflecting a true UX review for Quento, please allow me to shed some light on the design background and the things we did to provide the user with the experience they have right now.

    Quento originated from an idea to have a full RPG-like math game with a little wizard to progress through levels, and we came to the conclusion that the game concept itself could stand out on its own merits without a thick layer of paint and awards and whatnot.

    When we decided to go for a minimalistic approach 1.0 release to test the concept, we went for a design that fitted this new approach, and it became a buttonless interface. Not to say that buttonless is better than having buttons (most often it just isn’t) but in this case it underlined the UI design choice and minimalist approach for the game. So with that, we tweaked a lot to show the user what to do without having all such “tutorial this” and “pause that” buttons.

    The intro screen is such an example. It is there to give a subtle hint of the game’s mechanics, by needing to swipe a word. It gives the user the direct understanding of needing to swipe in the game, and when you start the game for the very first time, a tutorial pops up. It shows the most simple challenge, a puzzle with 2 numbers and a text explanation of what to do (which is more verbose than the other challenges once round 2 has been reached). This implementation followed after the initial feedback that -without something like this- you needed a person so tell you for the first time what to do, but not always a person is there to tell you, like when you simply download the game from an app store.

    This intro screen and tutorial really improved the response. Friends and family where introduced to the game without any intro and they understood the game’s mechanics, even the puzzles with 3 numbers were understood.

    Then, tips were introduced at specific rounds to give little hints on other possibilities. They include just enough text to tell you where Free Play mode is, or how to toggle challenges on or off, and people valued these tips for exactly what they were meant to do.

    Also, toggling challenges on or off has been implemented to address the situation where – without – it was either too difficult for young kids, or too easy for adult mathematicians. This UX change has made us receive many mails about how people love this new feature, so with that I wish to illustrate that we take this game and its UX all very seriously.

    As for the next version – we are creating a new Quento that will be a huge update and addresses some of the things we feel can be made much better. It will have levels and increasing difficulties (which is perfectly possible but is not in the current version) so it will offer replayability, with new timed modes and stars that you can still unlock of previous versions. Plus, a multiplayer mode where you can invite other players, and if they don’t have the game yet they will get a picture of that puzzle so it immediately provides them with a little braintrainer which might be enough to get them to download the game.

    Bottom line, I’d like to again thank you for your analysis, though IMHO you only shed light on one aspect and not went a bit further and spend time on all the other details wich are obviously there and indeed visible to UX experts such as yourself, or at least that is what I (and others here) feel is the case. I have to agree on the drastic shaking, though I also have to add that you are really the first one to complain about it publicly – whereas we have received many more reactions on other aspects on the game, such as the desire to mute on Android or toggle difficulties one by one.

    I am truly interested in receiving your feedback on the future update that we are building and will see the light in a month or 2 or 3. Please contact me through my email address if you like to receive a developer build of the game when it’s nearing completion. I really would welcome your feedback and will definitely use it for any final tweaks before release.

    Whoa, this reply got a bit over the top in length! 🙂 Just consider that my enthusiasm for UX.

    – Martin

    • Hi Martin, wow thanks for the detailed explanation. In an effort to keep my posts short, I usually like to focus on just one aspect of a game, and in this case it happened to be about the shaking mechanic. Yes, there are definitely a lot of things about Quento that I really think are great – the title screen is an excellent example, and one that deserves a post of its own (I have a thing for title screens for some reason). I certainly wasn’t intending this to come off as a full-on UX review of the game by any means, although now I see how my efforts probably were counter-productive. I really appreciate the feedback!

      The rest of the updates that you’ve got planned for version 2.0 sound like a good iteration on the framework that you’ve got laid out, and I’m looking forward to it. I keep getting flashbacks of playing Number Munchers back on the Apple IIe, which may be my favorite math memory of all time =).

      I’ll send you an email about some feedback on the next version; I’d be happy to offer any input I can. Thanks!

  3. And I forgot to mention the details in the user interface, where tapping and swiping are both allowed, combinations of that (start a tap, finish with a swipe), understanding that when tapping – certain situations will allow no further tapping and the game just tries your current tapped formula. Also, one UX choice was to visually separate Free Play from regular play as to underline the difference in puzzle mechanics. The black and white visuals for Free Play have received much applause through email and twitter where people felt that it really was a different more free game without restrictions or pressure.

    All those are UX aspects we really spent time on, and have received positive feedback on, and the negative feedback (Android not having a mute button and initially hide the status bar) have all been changed.


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