Hardcore mode is not fun, at least not to me. If you die it is game over. This means you could play for 20 hours, get to level 29, die, and it would be game over. Start again from scratch! There is a silver lining to this though. If you complete a level, exit the game and backup the game save. If you die in the next level, you can quit and restore the game save and start the level again without actually having to play the entire game again. Once you get the swing of things it isnt so bad. You should wait until you are more experienced with the game before doing this. Once you have found a class you like and are good with, you will find yourself flying through the game on hardcore mode.
Reach level 30 as any class on Hardcore mode