I got this a year ago and have fooled around with it here and there, but never had an actual reason to play it other than for fun. However, that changed when I got the idea for a character I made for a potential Dungeons and Dragons session.
My character is going to be a Wizard; however, while he has a deep connection to magic, he has problems weaving it together into spells, especially ones that he has studied and attempted to memorize. Every time he tried to memorize or copy a spell into his book, it fizzled.
Then he discovers a secret journal that details an ancient mage's spell crafting (IE Sigils in the Dark), and learns that if he creates his spells from scratch like this, he is able to harness the magic and actually cast them.
Mechanically speaking, I create the spells using the game, then reference them to spells available to wizards at whatever level I am learning spells with, and the closest spell (based on name, description, effect, whatever is the closest match) becomes my learned spell, so instead of picking and choosing, I am letting the game decide what spells my Wizard has. Figured it would bring an interesting chaos to the game, and if it works well, I may do that for other games where I play a spellcaster. And if the spell isn't available to a Wizard (the first one I made was an almost match with Heat Metal based upon the effects, but alas Heat Metal isn't normally available to Wizards), then the spell backfires and becomes unusable.