Icosi-Do cover
Icosi-Do screenshot
Genre: Strategy, Indie

Icosi-Do

Patch of demo D-19: more, faster, and cleaner music

Quite a bit of music-related stuff in this patch:

  • The big addition is a third music piece: Prelude in G-sharp minor, catalogue number BWV 863.
  • A wrong note in the Prelude in C-sharp major was fixed and the tempo of this specific prelude was increased a bit.
  • The crackling in the music was reduced substantially.

In other news: Steam changed some stuff about how release dates are displayed and I used this opportunity to reveal the official release date of the full version of the game, which is November 11, 2022. I can hardly wait!

As always: please let me know any comments or questions!

Fourth Weekly October Challenge

This week, we are back to somewhat easier challenges than in recent weeks: All level 6 puzzles can be solved with 6 swaps, but the puzzles of this challenge can be solved with only 5 swaps.

Here are the 3 codes of the puzzles: 1912-06, 2941-06, 2873-06.

To play these puzzles in the demo, you first have to unlock level 6 by solving puzzles on levels 1 to 5. Then you start a game with NEW GAME (in the main menu) and select CODE instead of a level to enter one of the codes.

Enjoy and please let me know what you think of these puzzles!

300 years of Bach's "Well-Tempered Clavier"

As I'm working on integrating more music by Bach into icosi-do, I learned that the first book of "The Well-Tempered Clavier" (which includes the preludes that I'm using) was dated 1722, i.e. exactly 300 years ago!

You can read what DW reported about this anniversary (in English), and - in case you are in Germany - you might be interested in a special exhibition about "The Well-Tempered Clavier" at Bachhaus Eisenach.

Also, the next prelude that I'm going to include in icosi-do is the Prelude in G-sharp minor (BWV 863), which you can listen to on YouTube:

Patch of demo D-18: more music, fewer instruments

I became a bit uneasy about having the same music piece playing over and over again. Therefore, I decided to have another look at the music for the game.


  • There is now a second music piece: Prelude in C-sharp major, catalogue number BWV 848, and a new setting AUDIO > PRELUDE which can be set to 846 (Prelude in C major, BWV 846), 848 (Prelude in C-sharp major, BWV 848) and CYCLE (alternating between the two preludes).
  • Listening to the new piece, I decided to remove two music instruments (FLUTE and CELESTA).
  • The names of some music-related settings were changed with the new names AUDIO > TEMPO, AUDIO > DYNAMICS, and AUDIO > DEVICE ("instrument" was too long). Also, the name GLOCKEN was changed to BELLS.
  • And a small fix: LEVEL MENU > UNDO MOVE now shows the move limit only when it is active.

Next, I'll add a third prelude (probably the one in G-sharp minor) to complete a triplet.

As always: please let me know any comments or questions!

Third Weekly October Challenge

This week's challenge includes another three difficult puzzles on level 7 for everyone who feels that the demo is not challenging enough.

The level codes are: 9219-07, 1208-07, and 9988-07.

To play these puzzles in the demo, you first have to unlock level 7 by solving puzzles on levels 1 to 6. Then you start a game with NEW GAME (in the main menu) and select CODE instead of a level to enter one of the codes. (Make sure that MOVE LIMIT is turned ON in SETTINGS > MODES.)

(If you are looking for more puzzles of this kind, here are the codes of the First Weekly October Challenge: 2226-07, 3361-07, 3952-07 and of the August Challenge: 1861-07, 4736-07, and 9962-07.)

Enjoy and please let me know what you think of these puzzles!

Patch of demo D-17: visual quality, resizeable window, waiting for V-sync, etc.

Now that Steam's Next Fest is over (thanks to everyone who joined my livestreams!), there are a couple of fixes of the demo that I should publish. I'm still planning to add an additional music piece, but that is delayed for a couple of days because of a tiny project in Rec Room that I want to finish first.


  • I had a look at visual quality settings and added a new menu item: SETTINGS > VISUALS > QUALITY, which may be set to LOW, MID, and HIGH. (Currently, this affects only the amount of multi-sampling for anti-aliasing.)
  • The game is now supposed to wait for V-sync signals in all quality levels to avoid excessively high frame rates (but you can still deactivate V-sync in the graphics driver settings).
  • The Tilt Five™ camera is now using image post-processing for a glow effect and an anti-aliasing technique recommended by Tilt Five (in addition to the anti-aliasing provided by the multi-sampling that is controlled by the QUALITY setting).
  • LEVEL MENU > UNDO MOVE now includes the number of the move (if there is a move that can be undone). It also includes the level number to remind you of the move limit.
  • The game window is now resizeable. (Because I was annoyed during my livestream that I couldn't resize it.)
  • There are a couple of changes to stats, achievements, and leaderboards, which are not relevant for the demo.


As always: please let me know any comments or questions!

Fourth Weekly September Challenge

With a bit of a delay, here is this week's challenge: All level 6 puzzles can be solved with 6 swaps, but the puzzles of this challenge can be solved with only 5 swaps.

Here are the 3 codes of the puzzles: 7784-06, 7870-06, 7887-06

To play these puzzles in the demo, you first have to unlock level 6 by solving puzzles on levels 1 to 5. Then you start a game with NEW GAME (in the main menu) and select CODE instead of a level to enter one of the codes.

Enjoy and please let me know what you think of these puzzles!

Patch of demo D-16: new mode signs, starting level 1 by default

Another tiny patch before Steam's Next Fest. As I'm thinking about achievements (and leaderboards) for the release, I decided to change the signs following level numbers (in SOLO and COOP games), which indicate the current "mode".

In practice, the important thing to remember is that you are no longer in a regular game when a "-" is following level numbers.

The details are a bit more complicated:

  • If a new game has been started on a level greater than 1, or MOVE LIMIT is off and COLORS are on (or they have been at any time during the current game), then level numbers are followed by "-". This is the easiest mode, which is good for unlocking levels and for trying out individual puzzles.
  • If a new game has been started on level 1 and MOVE LIMIT is on and COLORS are on, then level numbers are followed by "+". This is the usual mode to play "regular" SOLO or COOP games.
  • If a new game has been started on level 1 and MOVE LIMIT is off and COLORS are off, then level numbers are followed by "X". This mode is much more challenging than the former modes.
  • If a new game has been started on level 1 and MOVE LIMIT is on and COLORS are off, then level numbers are followed by "*". This is the most challenging mode.

To remind players of those relations, the signs are shown when setting MOVE LIMIT and COLORS (via SETTINGS > MODES) as well as when choosing a starting level for a new SOLO or COOP game.

And because regular SOLO and COOP games have to start on level 1, players are now always prompted to choose level 1 when starting a new SOLO or COOP game. (My current planning is that only SOLO and COOP games that have started on level 1 qualify for leaderboards.)

I hope this makes at least a tiny bit of sense. I also hope that it feels much more natural in game than in writing. Please let me know any comments or questions.

Patch of demo D-15: back to colourful intro

Just a very small patch to make the intro screen ("ICOSI-DO DEMO") colourful again after the last patch removed all colours from the menu texts by default. I realised that that intro screen needs colours for a couple of reasons. So, now that particular screen is always colourful - regardless of the settings.

Also, I fixed a purely visual issue with the menu bar at the bottom in the AR GLASSES menu.

(Usually, these things could wait a bit, but Steam is about to ask journalists to look at demos of games at Next Fest on Thursday.)

Dev Live Stream: Still Testing

Yesterday's stream had some issues; in particular because the quality of my internet connection is ... volatile, and I created some echo - probably by having the stream appear in my Steam client window. I'll try again today with a lower resolution, lower frame rate, and lower bitrate, maybe that helps to avoid the frequent disconnects.