As a senior citizen, I like this game because:

• it engages my mind rather than my reflexes
  
• it follows a consistent set of rules
  
• it has large and clear fonts for reading
  
• it has clearer outlines for placement of objects
  
• puzzles are mostly deciperable through observation and logic
  
• tolerances for clicking are good enough for my impaired hands

This puzzle game requires some understanding of how to break up problems into small parts that are solved and and recombined into larger solutions.
The challenges are:

• placement of wires and parts onto a grid with a limited board
  
• writing small amounts of computer code
  
• working out how to get parts to communicate with each other

I find this game to being very enjoyable.

An accurate experience of assembly programming.

This game is task-driven, which means you'll have to complete tasks by programming for microcontrollers.

These microcontrollers are very realistic: Low-performance, low-memory and with limited number of registers (only 1 or 2).

After you finishes your design, you will have to debug and verify it. The game's neat and easy-to-use debugging ui made it fun.

Once you submitted your design, you'll see a bar chart comparing your design against your previous ones or other possible versions. A low-cost and power-conserving design is most liked after all.

Here I'd like to talk a bit more about its programming language. Being a embedded device programmer myself, I appreciate its design.
Pros to its programming language:

• Realistic. It almost contains every basic operation a modern RISC machine and even co-processors
  
• Simple. Much complex details has been cut off, such as addressing and bitwise operations, which is good for beginners
  
• Good puzzles. You'll have to think about synchoronization!
  
• Backgrounded. I work in China for now and I like its background of Shenzhen (though I work in another city)

Cons;

• Too simple. More instructions and features needed!
  
• No more! :)

When I found this game, I thought it's just a programming tutorial game meant for non-programmers. Being a professional programmer myself, all I expected was an easy ride taking no more than a few hours, similar in difficulty to that Google Doodle featuring a hopping rabbit collecting carrots; I just wanted to see the story, set in that legendary Huaqiangbei of Shenzhen, with the alluring reputation that any flashy electronic gadget that can plausibly be made are being sold by someone there. I was even planning to recommend the game to my 70-year-old parents, who were familiar with computers but had less experience in programming. The authors have even made a Chinese translation...it would just be what they need.

As it turned out, the story is indeed interesting and believable, although I was hoping for more. But I couldn't be more wrong about its difficulty. The game is by no means a programming tutorial; it is about as beginner-friendly as AlphaGo Teach (in other words, not friendly at all). In many ways the game is harder than real-world programming. It seems that the authors are not at all interested in teaching programming; the player is simply expected to know all the basic stuff and cope with severely limited hardware and unclear documentation, just like a real workplace. And it is like reliving the memorable bad old days.

The game's difficulty is not due to its use of assembly. Actually, I've always held the opinion that assembly language is not a bad choice for beginners, since it is so straightforward, without much of the complications of high-level languages that might be difficult to explain to beginners (e.g. the difference between shallow copy and deep copy might be hard to understand if one don't know about pointers first). The PDF manual was also fun to read; the fonts are so wonderfully inconsistent and the marketing-speak is sometimes hilarious. But by that time I should have realized that the game was not meant for beginners; no EE student is expected to be reading datasheets before first learning the basics on their textbooks, right?

Then comes the puzzles. The first few are not difficult, and there were also many interesting emails to read... but they do require me to put my programming skills to use, in order to organize the program properly (e.g. what kind of state should go into the accumulator) and make use of various small tricks to work around hardware limitations. The behavior of simple and XBus I/O pins are not described in sufficient detail, leading to a bit of trial-and-error; but then real-world documentation can frequently be unclear as well.

The difficulty quickly ranked up. By the 10th puzzle or so (e.g. the one dealing with laser tags) I began to realize how dreadfully limited each microcontroller is. A capacity of only 14 instructions and 2 registers (with only one of them supporting arithmetic)... for someone spoiled by today's x86-64 and ARMv7 chips with 16-32 registers, easily accessible memory, and programs with almost unlimited length, such limits are suffocating. Isn't the story set in 2026? It looks more like 1976. (On second thoughts, this might feel more similar to GPU programming, where the number of registers is also quite limited compared to the needs of typical numerical code, and accessing memory can be quite expensive.)

So the later part of the game is basically an exercise in extreme modularization. The requirements themselves are not complicated; actually they are probably very straightforward to implement on any modern chip. But given the limitations of the in-game microcontrollers, the player must implement the requirements in a way that uses a small number of instructions, split the implementation into small modules that each fit in a single microcontroller (this requires some trial-and-error; often much of the code has to be rewritten just due to a single instruction beyond the limit of 14), and design communication protocols among them. It can often be aggravating... but when I finally fit the code into each chip and they solve the puzzle correctly, it is also very satisfying. The design just has to be relatively "clean"; anything ugly will probably not fit.

By the last few levels, with the large number of chips needed, board area has also become limiting. Again, it is satisfying when I successfully fit all the chips and wires on the board, and frustrating when a single wire would not fit and major design changes are necessary, but now a single level can take over an hour to complete, and the frustration becomes overwhelming, especially since everything would be so easy on a modern real-world chip. Finally, after being stuck for several hours in the cocktail level, I decided that enough is enough, and it is nicer to do paid programming on modern chips.

I recommend this game to experienced programmers, who will probably receive a reasonable challenge and end up appreciating their real hardware more. For non-programmers, this game is probably too difficult as a programming tutorial; it is likely much easier to get a textbook and learn real-world programming, be it in a high-level language or maybe just x86-64 assembly.

Maybe the game could benefit from a lower "prototype" difficulty, where program size and board size are not limited, and the player just have to implement the specifications correctly. When the player successfully fit the solution into the current program/board size limits, a medal can be awarded.

Nothing better than programming after a long day of programming at work

I like to relax after a long day working as a programmer by pretending to be a programmer

I've been coming home from my programming job every night to my fake programming job which is a lot more fun.

Shenzhen I/O is a great puzzle game, if you are up for the challenge. I am actually an Embedded Systems Engineer, and this is what I do for work, and I can say they did a great job. Obviously, there are several things that aren't realistic, but the great manual with terrible data sheets is accurate. I loved the addition of the Chinese only data sheet.

I just started a YouTube series based on the game (shameful plug), called Shenzhen I/O in Real Life. I am taking one of the puzzles and showing how a real Embedded Systems engineer would actually design one of the projects, so come check it out!

Its like TIS-100 but it more effectively mocks my career aspirations.

Love going back from my programming job, to do some more programming in a game.

if you're a programmer and you love to work after work, this is for you