Combining classic elements of Tower Defense games (build towers, strategically place them across the map and destroy the critters) with RPG elements (leveling up, combined gems for more power) and a wide variety of weapons (you can basically combine any type of gem with another and get an unique weapon), GemCraft is indeed a high quality game that will test your skills and entertain with its variety for a long time now.
Because, even after you finish the normal game, you can replay it with the same pleasure using different other game modes, like Arcane, Bleeding Edge, Swarm, Sudden Death and much more – all available once you reach a certain level. And yes, I must admit that this mixture of RPG elements with the classic and entertaining Tower Defense genre is a real hit and I am surprised we are not seeing it used in many other newer games already.
But that should not worry us too much, though, since we still have GemCraft, today’s free flash game of the day I really urge you to try.