Do not open this suitcase: devlog


I still haven’t formally introduced my new project, so, here goes!

(“a bomb in miami, 1992”)

One of my favourite video games ever is keep talking and nobody explodes, which is a completely novel concept for a computer game: One person deactivates a bomb (on the computer) whilst a whole group of people give them instructions via the bomb defusal manual, which is made of paper. have a look. The experts can’t see the bomb, and the defuser can’t see the instructions.

For at least a year, I would think to myself “how great would it be to make a real (pretend) bomb and play this in real life?!”. But, I thought it would involve learning a whole new host of things: arduino, for example, or, just how electricity actually works. I didn’t even know where to start.

That’s when I remembered a gadget called a makey makey (have a look). I’d been dismissive initially, (how much fun can you really have with a piano made of bananas?) but there was one moment where my brain just clicked, and I thought: oh my god, I could actually do this * It was like being really hungry and suddenly remembering you have everything you need to make a tortilla de patata.

*nb it turns i can’t actually do it, or not yet anyway, but we’ll get to that later.

I realised just how little actual coding I’d have to do in order to make this work! All of the confusing bits happen in “real life”: you have to change switches, disconnect cables, open locked boxes, fix keyboards, enter numeric codes on a keypad…I could run it all from an android phone with a few external peripherals… so I got started

I went to a local second hand shop and got some amazing stuff… a samsonite lockable suitcase, an old slider viewer, a lockable cash tin…and started putting it all together.

the suitcase:

the slide viewer (which i took apart to get a lense to make a kind of retro screen)

the cardboard prototype of the “controller” (currently being made by a carpinter!)

I am actually going to cover the wooden prototype in this horrible wooden patterened stick-on plastic:
(that’s the kind of look I’m going for, image is from google)


Well, I decided i wanted this to be QUICK, and in the past the graphic design element has always taken me a long time. So I decided to go retro, which is always pretty fast.

and… that’s basically the only screen there is, some other elements appear, but the screen hardly does anything.

Oh, and here’s the noise the bomb is going to make when you open the suitcase.

I decided to make it as 1980’s as possible, from the name to the design, to make sure nobody could possibly take it seriously (it actually looks terrifying right now. Once I have the carpenter’s wood back I’ll take some photos of the final project).


Well, I gave the carpenter all the information he needed a week ago and he hasn’t even told me how much it’s going to cost yet, so I’m slightly worried he’s not going to do his part. But that’s not a big problem, I could easily make the box out of cardboard. The main problem (as many of you are already aware) is that android apps created in defold don’t accept input from USB devices connected via USB-OTG! I am not too worried, though, as I know @britzl is working hard on that, motivated by a mixture of reverse psychology and me threatening to burn all my stuff, like an angry teenager.


This sounds just incredible! I also love Keep Talking And Nobody Explodes and it really tickles the child in me when you describe the “real thing”. Wish you best of luck in your project!


Thanks Andreas!

I have a deadline of THIS FRIDAY to finish all the work, when I am going to take it to a fest in Bilbao! So expect more photos/videos soon

my bit is done, so unless it turns I need to make the box myself or the android USB keyboard thing doesn’t work, I can’t see any problems


Holy cow! Great work! This is absolutely brilliant. Patent, copyright, mass produce. I’d totally buy this game.


Well, I suppose that’s an alternative to writing a CRT style shader… :laughing:

Really cool idea! Will be cool to see the finished product, I hope it goes well.

What device are you running the game on? Android I gather, but which model?


Thanks for you kind comments!

I have been thinking about how you might make money out of this, and the problem is that each game is very similar to the one before. Keep talking and nobody explodes works because it had an online community modding it (and because each game is randomly generated, and has a large number of potential problems to solve to deactivate the bomb), but with a real-life version, it’s something you can only do once or twice (or three times) before you get bored. Because the controls are always the same. But, I’m glad you like it (I should say, many other people have had the same idea before me, if you look on the internet there are various examples).

@tacklemcclean it’s android 6.0 i think, on an old Moto g4. From a computing point of view it’s incredibly simple, except of course for the controller situation.

Once I get back from the carpintero I’ll give everyone an update!


I think you might be able to write lots of total different puzzles with different gui and visuals on screen even if you are using the same controllers. KTANE was restricted in that the controllers were exactly for one puzzle each. You could definitely use the screen more to come up with different puzzles in combination with the controllers for longer fun and gameplay.
Eg. In one puzzle you need to click on the keypad to change digits on the screen, in another the keypad gives away morse sound and in a third it might change colors/patterns on screen.


I have been thinking about this a lot, and how the game should be “pitched”, (and also what @GamingBud mentioned about mass production), and I kind of think that for most people do kind of get bored of the novelty fairly quickly. I could literally play Keep Talking and Nobody Explodes forever, but, part of my job sometimes involve playing that game as a team-building exercise or as an english-teaching tool and after a few games, most people find that it does get a little repetitive. I prefer to change slightly the KTANE model, by making it a bit more like an escape room: an experience that you just get one chance to do, right or wrong.

And, yes, it is possible with the limited physical controls to allow for random generation of problems (in fact, I have created a few different modules, each of them making use of various different controls, but I am only using the ones I like best. I’ll upload a video later). It would even be possible to make easier and more complicated versions. But, from interacting with it and playing with it, the idea of it being “REAL” is kind of … diminished if you know the game is randomly generated.

I also have some interesting things to talk about cheating. Not the player cheating, but the game cheating. There was an article about this on polygon a while ago, but I can’t find it. Basically, in my game, the ideal outcome is that you deactivate the bomb with a few seconds to spare. If you deactivate it with minutes to spare, it’s boring. If you fail to deactivate it and it explodes, it’s disappointing. So, I’ve done a few “cheats” to make this more likely:

  • If you are doing badly, the countdown timer goes more slowly. Not noticeably slower, but just enough to give you a total of 7 minutes instead of 5, for example.

  • you start the game with three hearts. You might think that for each mistake, you lose one heart. But the last heart has various parts: first you lose a half, then you lose a quarter, and then you lose completely and the bomb explodes.

  • I don’t want to give too much away so I’m going to be as vague as possible about this: the last part of the game involves solving a problem which randomly changes a value that appears on the screen. When that number is 0, you can disconnect the large, coiled cable from the explosive material and stop the explosion. However, the randomly generated number is not actually random !! If you have more than 30 seconds left, it’s impossible to get a 0. But, once you have less than 30 seconds left, you have a one in 5 chance. When you have less than 10 seconds, the computer always gives you a 0.

Another image (this time, from the bomb-defusal manual):


Also, what do you think about the name


compared with “A bomb in Miami: 1992”


“DO NOT OPEN THIS SUITCASE” may be better because it provides more of a focus on the game. “A bomb in Miami: 1992” makes me think of a visual novel or a game with story elements tied in.

Although, “DO NOT OPEN THIS SUITCASE” is long. I’d recommend shortening that to something that flows off the tongue or something along those lines.


@GamingBud yeah, I did originally wanted to make a whole universe (actually, a friend and I are still planning on making a short film to advertise the game which will be like a 1990s cop drama). That’s why we went for that name. But, it looks like we won’t have time for that right away. The name “do not open this suitcase” is obviously a long name, but I like the fact that it’s unweidly. Also, “keep talking and nobody explodes” is another example if a terrible name for a game!!

See this video for an interesting point of view on naming.


I just saw this post on Defold’s Facebook page (completely missed it here on the forums, thanks @Oleg_The_Evangelist). I was wondering what were you doing with a Makey Makey and honestly this is just so cool! Good luck with it! If you showcase it somewhere, don’t forget to film people playing it.

*reins in impulse to install KTANE on my work laptop*

P.S.: Small OCD note: Add some inner padding to your atlas with the hearts, so it won’t show those sampling artifacts.


If you don’t like the artifacts, @dapetcu21, you’d absolutely hate to see my code!! haha

But, yes, that’s all sorted now. Thanks for your advice.


mmm… maybe we should use Facebook more often then.


Show case is on saturday this weekend (unless I don’t finish it)!!!


Yes!!! it gave me an incredible sense of pride!


It has been an incredibly long day but I am getting closer to the end.

I am going to add some stick-on wooden panelling to the computer to make it look more 1970’s (and less actually scary)


Don’t get caught commuting with that!



If you start recording the playtests to your youtube channel, then you’ll have your community by the end of development. Soo… did it sound inspiring? =]