I tried writing a simple procedurally generated rpg game in Java after a year in the Computer Science program. It was entirely text-based and suffered from horrible balancing issues. After a while, the player character outscaled the monsters and you would basically be unkillable.
Here is a little snipbit of the console log:
While the game was not very good, it was a great learning experience. It forced me to consider various things like character stats, some way to implement a random damage calculator that scaled depending on things like levels and items, and some system to procedurally generate enemies based on the player character.