Bosses are not included here to limit spoilers. You will find them covered in their respective level guides.
Hover Tanks are the more numerous, mobile enemies you face in the game, coming in three varieties. These will often spawn or be found in groups, posing little threat on their own but becoming dangerous in their large numbers.
Heavy Tanks are types of large mobile enemies that often travel very slow but come armed with several weapons that can easily wreck your Tank. Extreme caution is advised against these units, best fought with the advantage of nearby terrain.
Turrets are stationary defenders that while incapable of movement, still typically pose a serious threat given their weaponry. You will often find a couple of these enemy units will be teleported in with some additional Hover Tanks during an ambush.