Even after about fifteen years in computer science, I'm not really sure what 'hacking' entails. Hollywood hacking is one thing, opening some file with an hex editor and changing values here and there is also a form of hacking, is Hacknet showing a form of hacking that exists? Are there port-scanning tools that you can run on remote IP addresses to break security and then get root access in remote computers? No matter, my curiosity aside, Hacknet is really neat, I'm not sure if it's 100% accurate, but it does use some unix shell commands, makes you do hacking missions with an interesting storyline and makes you feel really happy when you type that final command to finish a hack while looking at a timer counting down.
Everything is on a computer in Hacknet, you start on your own machine where all your programs are stored (and most documentation/random files you find during the game) and from there you can connect to external computers, mainly for story missions and quests. The loop goes like this; You find the right computer to hack, then you see how many ports you need to open before you can crack the system. There are a few types of ports and they all require you to use specific programs to hack them. Programs require RAM to use, so you can't hack everything at once. Some programs you get later on, like the one to stop Traces, takes almost all of your RAM, so you can't deploy it at will. I wish there was a way to upgrade how much RAM you had, I know that it's there for balance reasons, but it becomes really annoying whenever you try to do something but have to wait for other processes to shut down.
As the complexity ramps up, you have to overload a proxy by connecting to a remove server and running commands there; then you'll bump into firewalls, which require passwords that you gleam from a grid of letters. After a while, Traces come into play; timers that count down to 0 while you hack, adding a very stressful element to the game. The rules that govern hacking a machine are vague at best. If you overload a proxy/hack a firewall/open any ports and then disconnect, they'll all be back to normal when you connect back, the firewall password doesn't change so you can save some time there, and if you had hacking programs going on, disconnecting won't stop them, so you can start a few of them, disconnect and reconnect to reset the Trace timer. That doesn't feel like the intended solution, but I did it anyways. Then you find what you need, scan file systems, read IRC logs, decrypt files and probe networks, and finally you delete everything in /log/. I'm not sure what happens if you don't, because I did it every time.
If your Trace timer goes to 0, the game freaks out in emergency recovery mode. This was very stressful, but also an awesome moment in the game. The game said that it would delete your progress if you failed, but I really wonder if that was true. In any case, the game is full of cool moments. I had to look at some walkthroughs because I couldn't figure out clearly what my next step was in some missions and I was getting sick of having to hack the same computers over and over because they kept reverting to normal, but in general I thought I knew what I was doing and I enjoyed doing it. I finished Hacknet, so it's a really neat game, I just wish that there had been a polish pass on a few things because the frustration kept me from enjoying it completely.