Protect your gems from being stolen by good heroes in this tower defense game.
Overlord, you have all the power of orcs, undead and demons.
Use mouse (hold SHIFT to build multiple towers or cast multiple spells).
The game has a bult-in tutorial.
Try to annihilate the enemies before they grab a gem, but even if they do, you will have a chance to annihilate them on their way back and you will save the gem.