Ground Defense is a mini-game that was originally played on Skylanders: Universe. It involves protecting your treasure from a bunch of raiding Sky Pirates using your Skylander. Unlike the Spyro's Adventure, you only had one attack plus specials (the number of specials you can use is based on how many Skylanders you've registered), which vary by element.
Enemies included a variety of Trolls and Spell Punks, the latter using support spells for the other raiders.
Trivia
This game frequently caused Skylanders: Universe to crash, as later waves introduced too many effects from Spell Punks at once if not dealt with quickly.
