GemCraft is a fantastic tower defense game that you can play online and for free on Silvergames.com. The mission of the game is to defend your base against monsters. Create Gems and place them into towers.
Only towers with a Gem in them can shoot the creeps. The left bar shows you the next wave of monsters and also how strong they will be. Click on a monster to see a short info about it. Have fun with GemCraft - The Forgotten!