As a person who likes typing tests this was fun! There's not much to it beyond that, but that's fine because that's the game. Some bleep bloopy Deus Ex-style music would add to the Hacker vibes. Maybe sounds effects for wrong/correct entry as well as timeout and success. Ticking sounds for the timer that got more intense or harsh as the time ticked down would be cool as well.
I struggled a bit with the second scenario, however on the third scenario I realized I could just copy/paste the command I was supposed to enter. If you release left mouseclick it unselects, but you can press Ctrl+C while holding it. This made the third challenge trivially easy.
“Given the opportunity, players will optimize the fun out of a game.” - Soren Johnson