While only adding two levels to the original game, the first part of the Hardcore Package is both challenging and engaging, adding an hour and a half of content to Hacker Evolution.
The first level alone took me a whole 40 minutes to complete on my first actually successful attempt (I made a major mistake about halfway through the first time) and that success felt as though I had truly achieved something. The second level is slightly less challenging and slightly shorter, but no less engaging. All in all a worthy addition to the game.
Of course if you don't enjoy the game itself then this DLC won't make it any better for you so make sure you've given the base game a go first to figure out if you like it but if you do enjoy Hacker Evolution then this is probably worth the extra cost (and it is definitely worth it if it's on sale).