From that point on, expansion continues and the player can begin to construct offensive units to form their army. (gamesnosh.com)
This means you will also have offensive units as well and not just towers used to defend your own base which is where the tower offense part comes in. (droidgamers.com)
This actually combines tower defense with offensive strategy, as you must not only use units to defend your base but use your resources on offensive units who can take out your opponents. (lifewire.com)