At the start of the game, the player is given their choice of three different nanorobots to choose from, each with different amounts of speed, strength and stealth. Speed is the speed of the vessel, stealth is how likely the body is to reject the vessel as a foreign particle, and strength is how well the machine holds up when under attack by the body. This module is played with the mouse and keyboard and is very similar in style to a flight simulation/combat game only played inside the body with dodging blood cells, platelets, and particles instead of dodging enemy fire and attacking cancer cells instead of enemy bases.
