I have not yet bought the Magician's Pouch, but I consider it a good way for this company to make money on a fantastic game that they are letting you sample in a BIG way for free. We can't expect people to make entertainment without getting paid, and this is worth paying for!
I know that this is an old game, and not as cool as it's newest descendant, Gemcraft-Chasing Shadows. But it is still a fun, challenging tower defense game. Not the best game for occasional one-offs, but if you like working on your own strategies it's lots of fun.
 "GemCraft - Chasing Shadows"){kind=icon}
 "GemCraft Labyrinth"){kind=icon}