CraBot was the first enemy type we made for the game and it is quite a straightforward melee class enemy unit that chases you around and tries to slice you to bits with its claws.
Guards on the other hand are more diverse enemies that have a wide variety of tricks up their sleeves. They form the back bone of the Island Delta security. They are very aggressive units and will gun down any intruders on sight. They will also knock you down should you get too close.