When you level up and it becomes more powerful, magic becomes more expensive to cast. Some people thought that wasn't that good an idea.
I can't really tell if what you describe was intended or not.
But it is what it is. The game had been tested extensively, has been out for a long while and I've fixed lots of bugs. Any gameplay mechanic is a feature now.
Originally I was only the graphics programmer and had no hand in creating gameplay. The programmer (Steve) who was responsible for that has left us a long time ago. We are a very small team, just the two of us, and at this point in time we have to concentrate on our new game(s). I hope you understand. (Obviously I'll try and fix any crashing or game-breaking bug.)