Hackerman

[Source (Gist)]

Greetings, Hackerman.
Welcome to the Simulation.

To your right is the Hack-o-meter, which evaluates your performance.
Any hacker worth their salt wouldn't allow it to deplete.

Hack away at your keyboard to keep the hack-o-meter up, but keep in mind that each stroke temporarily disables that key for short period.

White "Critical" keys will appear periodically, and if missed, will incur a penalty.
Successfully striking a critical key will cause the next to appear immediately, and may potentially reactivate an otherwise disabled key.

Your hacking program will take a certain amount of time to complete. It's your job to keep the security system distracted long enough for it to open the backdoor. Once completed, you'll have to evade the Watchdog Protocol by bringing your Hack-o-meter above a certain "escape-threshold" (indicated by a red line on the Hack-o-meter), then hit [ENTER] to execute to hack.

Select [LMB] your training exercise using the colored switches on your left.
Green is the easiest, through to Red, the most difficult.
When ready, press the indicated [ / ] key to begin.

Introduction complete.
Godspeed.