There are currently 3 types of Heroes: Energy, Biochem, and Mechanical.
The type of Hero determines what the Hero is strong against and what it is weak against. Energy is strong against Biochem, Biochem is strong against Mechanical, and Mechanical is strong against Energy. Attacking an enemy you are strong to causes you to do more damage, and they do less to you.
When fighting a opponent Hero, you can tell if the current Hero you're using is strong or weak against them by the up arrow or down arrow displayed when aiming at the opponent Hero.
The type of Hero determines what the Hero is strong against and what it is weak against. Energy is strong against Biochem, Biochem is strong against Mechanical, and Mechanical is strong against Energy. Attacking an enemy you are strong to causes you to do more damage, and they do less to you.
When fighting a opponent Hero, you can tell if the current Hero you're using is strong or weak against them by the up arrow or down arrow displayed when aiming at the opponent Hero.
Note that some enemies may be grey (no type) and receive no damage bonuses or reductions.