About BoltKey


MiniLD #72
Ludum Dare 37
Ludum Dare 36
Ludum Dare 35
Ludum Dare 34

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Just pick a number – now on Kongregate!

Posted by
Monday, April 3rd, 2017 2:24 pm

So, I finally moved to https, which means I can finally make my projects that use databases and stuff get to work on Kongregate. If you haven’t yet, go play Just pick a number there!



Posted by
Sunday, February 26th, 2017 2:37 pm

A grid-based fast-paced quick action puzzle game. My first Mini LD entry! Play in your browser!

I didn’t have much time to polish it too much, but it works and is pretty fun to me.

I wanted to make a game with simple rules, addictive gameplay, short play time, and combining quick reflexes and thinking. Did I succeed?


Just pick a number – data analysis!

Posted by
Friday, February 17th, 2017 5:09 am

Hi! Some of you may remember my game Just pick a number. I placed #23 overall, and #6 in innovation. I finally made some data analysis and a blogpost examining the findings. Enjoy! Below is a time time-lapse of the graphs.


Those are two important lessons I learned this LD. If you feel like reading… boltkey.cz/blog

Prisoner’s dilemma themed game

Posted by
Sunday, December 11th, 2016 2:51 pm

“Pick a number between 1 and 10. You’ll get that many points only if that number was selected by less than 20% of other prisoners”

Just pick a number. I had to start over 12 hours in, but I am quite happy with my thing. I finally made some non-terrible graphics and sounds for a game, so that is a success in itself for me. I mostly want to just see what the graphs will look like after hopefully several hundred plays.

I’m in

Posted by
Friday, December 2nd, 2016 11:35 am

4th time. It’s been a year since my first LD, the time really flies by.

I am not very proud of my last LD and I am really motivated to make up for that this time. I will work more on time management throughout the weekend and make sure the concept I will implement is good before wasting 10 hours on it.

I will try to keep it simple this time, but really work on the gameplay. I would love to finally make some rts perhaps. But who knows.

JavaScript + html5 + css
Maybe Bosca Ceoil if I want to make music
Some auto screenshot thing + Virtualdub + windows movie maker

I was born ready for this one.


Posted by
Sunday, August 28th, 2016 2:03 pm

Third LD complete. I think it doesn’t look horrible. I am quite proud of my game actually. This is probably the most graphics-heavy game. You can tell that the sea is sea and not sky and that the ships are ships and not airplanes. Which is a success for me :). Also, it ended up being quite fun. I had to make the ship speed much faster than I first intended, because else it was very boring.

I had to start over after 9 hours of work and give up on idea of letterpress printing company. But I am glad I did, that idea just… didn’t work.

The game


Beholdate Heatus Rayus!

Posted by
Saturday, August 27th, 2016 9:34 pm

It is coming together nicely. I am really tired, so my Latin/English sounds probably really stupid. Gonna catch some sleep and finish this thing off. Meanwhile, enjoy some Greek guys talking on a beach.


In case it was apparent, those are Archimedes’ rays.

First gameplay

That gif has somehow messed up colors. Oh well.

Have you ever been absolutely mesmerized by a beauty of a bug?

Posted by
Saturday, August 27th, 2016 8:55 am

Beautiful. Just try to refresh several times to get great patterns.

Progress on my letter press

Posted by
Saturday, August 27th, 2016 5:23 am

Now just add some evaluation system, story and others, and I got myself a game! Looking good so far.


I’m in

Posted by
Monday, August 15th, 2016 6:49 pm

This is my third LD. I am really happy I get to attend so historical event like this.

I like to set myself a genre before theme announcement. Last time I said I would do a grid puzzle game, and the theme worked kind of well with that.

This time I would love to make a real time strategy game. Or at least turn based. Let’s see what themes there will be and if it fits that genre at least remotely.


  • Language: HTML5/JS
  • Editor: notepad++
  • Debugger: Chrome
  • Sounds: sfxr
  • Music (?): BoscaCeoil (I would love to compose some piano song perhaps)
  • Graphics: GIMP
  • Recording/video editing: Auto Screenshot Capture by daanav + Virtualdub + Windows movie maker (shameless)
  • Version control: Git + Github

I can’t wait for all that to start again. I will give it my best. I can’t wait for all the food, coding till the morning sun, browsing other entries, getting feedback. I am so glad Ludum Dare is happening again.

I have been doing games without graphics for a while now. I decided to try some graphics for this Ludum Dare, and tried to add various generated sounds, go play it here. It turned out bad. I compare it with my other puzzle projects, which used almost no graphics at all (only colored squares), and they had quite a success. But this one, it has rating of 1.9/5 on Kongregate so far, compared to gameplay wise very similar games like Order line or Overspill, which are without music and graphics and with very few sounds, and they have rating of about 3.3/5. I think it is mostly because of the graphics and sounds, which, let’s be honest, look like they were made by an 8 year old. So yeah. If you can’t draw, keep it without graphics. If you can’t make music, don’t make music.

My assumption was that if there is a mute button, music and sounds can’t make it worse. I was wrong. It is all about the first impression.

I could just remove all the graphics and sounds right now, but 1: I spent so much time on that I just can’t, 2: I want to keep it this way as a deterrent for me and all the other devs for the next time I ambitiously try to create my own graphics or sounds.

I could perhaps make a version without sounds and music just so everyone can see the difference bad graphics make.

Yeah. That’s all I wanted to say. No matter how bad my thing turned out, I am glad I learned that lesson.

I am excited about this. I already know my way around a bit better and earned some experience since the last Ludum Dare.

With final school exams coming soon, I can’t spend the whole weekend deving. So I decided about several things already. I am not going to use collisions this time. I had my game based on collisions last time in LD34, and it was cancer. I would really love to make a grid puzzle. They are quite easy to make, the main part is coming up with the idea. One of the reasons I am going to make a grid puzzle is that I suck at them, so I hope I can’t set the difficulty too high like the last time. It may be challenging to come up with a grid puzzle for some of the themes, but I think I will come up with something eventually.

Good luck everyone!

So, I heard it is cool to write post-mortem.

Posted by
Tuesday, December 15th, 2015 7:09 pm

This was my first LD. I heard about it before and played some games created for it without even knowing they were created in 48 hours.

I have to say it has been an awesome experience really. I wish I could thank you all individually for creating so great atmosphere here. Also, the voting system is genial.


Ok, enough praising. Let’s talk about my game.

What went good:
– I came up with the concept quite fast and sticked to it until the end
– I read some quides and stories by other LDers in advance, that’s probably why the dialogue is there
– I finally used git for my project
– I got enough sleep, so my productivity didn’t drop
– The music. It was actually my first attempt at music making
– I didn’t visit facebook or similar throughout the weekend
– I wasn’t disturbed by anyone

What went bad:
– My eating schedule was messed up. I had one HUGE meal throughout the whole weekend and nothing else
– I wrote some terrible collision code at the start thinking I will have not to return to it ever again, but turned out I had to adjust it a lot of times. This actually caused some bugs with collisions
– The difficulty. Let me talk a bit about this. So, I really like this kind of “skill” games, one example for all is Super Meat Boy (all bandages). Of course I want to make it fun for me, and I want the levels to be challenging. I create levels that are hard and nicely challenging for me, but combine some skill in the genre with designing levels which I know how to win, and you get impossible levels for other people. Which really sucks. You know, you spend most of the time on mechanics and features, and then you lose it all on level design. This exact thing happened with my earlier project, but I didn’t learn for some reason. The worst part is that most of the interesting features are in the levels 90% of the players will never get to. It has a grow mechanic, but I think nobody reached that yet. I really hope I will finally learn and start making proper difficulty curve.
– Too long levels perhaps? It is probably frustrating to have to go through the whole level if you die at the end


Anyway, here is a chronological log which I wrote up during the weekend.

5 hours till start
So, in preparation, I set up my repository, learned to work with Bosca Ceoil and sfxr for music and sounds, and I think I am ready. I can’t wait for this to finally start.

I had several ideas written up. I think I had an idea for about 10 themes. I lost them all because I forgot to save. Whatever.

Anyway, I have a little neat concept that could – with some tweaks – fit most of the themes. Well, not most, but some.

I really hope the theme will not end up being Growing. Like… what… would I do…

Control the environment… same…

I guess I will complain about theme anyway. I like isolation, stick together and strength in numbers the most.

I think I have everything set up, including food and beverage for the weekend. The best part is my parents are leaving the house for the weekend, so I will not have my workflow disrupted at all.

I think I better get to bed so I can get up and dev all day and all night and all day and half the night. This… is gonna be awesome. I really hope I will keep this blog running and updated.

Ok, I lied about the “go sleep” part. I set up the page, set up the canvas, made resize function and basic hello world. That is not considered making the game yet right?

Man I am so excited.

Ok, 4 hours remain. I will get hopefully 8 hours of sleep. See you, for real now.

Almost 8 am now, 5 hours in. The themes are the two worst ones. Two button controls and growing. Darn.

I at least have an idea about Two button controls. Acceleration game where you can accelerate into two directions and have to bounce off walls and shit.

Time means hours and minutes since start. Add 3 hours to get local time.

5:16 I got it going. I imported some input handlind from earlier projects and got menu up.

5:39 Level displays properly, let’s get into player physics.

5:44 Player displays and can be moved like I wanted him to. Next step – wall collisions.

6:28 Bouncing off wall finally works properly.

6:45 Ok, bouncing works. I should probably make a spreadsheed with todo and ideas.

7:18 Ok, now it works. For real now.

8:48 I got working on some dialogues and story. I will have to think of something funny. I am in the phase, where the core is working and I don’t know whether to add some features or leave them be.

10:25 My workflow is starting to slow down. I have no idea what to do next.

11:06 I just made music and generated some sound effects. Will implement them shortly.

12:19 Third level, yay. Music is not as terrible as I was worrying. The loop sounds a bit odd.

13:19 Ok, here comes the level designing. I have 2 tutorial levels and 1 real level. I think 2 tutorial is quite enough. I was thinking… maybe about 20 levels is just about right.

15:37 I took a little break. I don’t know what to do next once again. I even got the sounds done this time. Also, I said “screw menu”.

17:11 It works. I created quite a lot of dialogues to keep the players playing. Becuase the power of this game is in its later levels, and to get somewhere, I need something to hook people on. Getting close to half-time, and I am out of inspiration already. I added ice, which was probably a good idea. I need something else. Active powerups like for example instant stop is not an option with only 2 control keys. I was thinking maybe some speed upgrade, but that sounds a bit stupid.

18:03 Gravity changers. They turned out to be pretty good actually. Made one level with them, and it is awesome.

18:40 level 7 complete. I have a long night ahead of me if I really want 20 levels.

19:08 I will add some grow mechanics. While you are on a grow tile, you get bigger, making it all harder. Once you get too big (48px), you just explode.

20:39 I got the grow mechanic working. Now I need ideas for levels.

24:11 Half time, here we go. I was expanding my music, then accidentally hit Esc and lost like 1 hour of work. Darn. The music sounds like shit, but I will keep it in anyway. I tried to make the “graphics” look less like 5-year-old-made by making the colors cooler, but it seems it started lagging. Darn. The levels keep going, but I need ideas.

28:12 Night wasn’t as productive as I hoped. I have 10 levels now, and made new music. I just am out of ideas for levels dammit. I have enough game elements for various combos, but I just don’t know where things are stuck. I guess I will go get some sleep after 24 hours. I have like 10 hours of work available now, should be enough to finish this thing off.

36:30 I have 13 levels, and I think that’s enough. My play-through is about 30 minutes, so I suppose other people will have completion time somewhere around 1 hour. That’s fine I guess.

39:00 It is complete, but it NEEDS more levels. Some of the features are only merely introduced. I have 9 hours, I should be fine. But the rest is complete. And also feels complete. I haven’t even met that rare bug in two runs, it is not even worth to be bothered by. Also, my second run with adjusted levels was 15 minutes.

39:09 FUCK! It lags like hell in Firefox. Goddamn Firefox, I hate it even more that IE.

39:56 Phew. Fixed it. Note: Firefox takes for EVER to change ctx.font. Several adjustments to this fixed it, as I was changing it like n times every frame. I can’t even upvote the random guy who saved me on stackexchange.

40:08 I just realized I haven’t eaten in 24 hours. Weird I didn’t even notice it. Well, I ate had a shitload of lentils the other day, so I guess that’s why.

41:33 I made 2 more levels. But I need AT LEAST one more to make it 15.

44:17 I managed to hopefully fix one really bad bug with collisions. The size change fucked up everything. I added last very hard final level. It is done. DONE! The very last step is submission. Nothing goes wrong with that right? RIGHT?

47:57 I browsed around Ludum Dare a bit. I added several little things, but my ftp is fucked up. Hope it works.

My first Ludum Dare has been an awesome experience

Posted by
Sunday, December 13th, 2015 7:58 pm

Thank you all for making this possible. I am so glad I finally participated.

I think my thing turned out pretty good (better than I expected definitely), and I have 3 spare hours, which is nice. I think it turned out pretty difficult, can anyone beside me finish it?



Play on my website

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