The game is a form of tower defense where the enemy is an expanding liquid called creeper.
The main objective of the game is to destroy all emitters and any gates on each map to progress to the next. Failure occurs if the Creeper manages to reach your ship and destroy it.
Rather than the top-down view of the original Creeper World, you're given a side view which offers an easier visual of creeper depth. Also brought in due to this new perspective is the advent of mining ore. And when is this ore used? Why, when you start producing anti-creeper. So, along with your trusty blasters and launchers, new to your arsenal are the makers, which produce the anti-creeper, nullifiers, which destroy emitters, repulsors, which push creeper back, and phantom coils, which are used to take out Phantoms (spores).