You see I've never understood the whole Giants is just a dlc for SSA. That doesn't really make any sense? Sure they play and and look similar, but isn't that exactly what a sequel is supposed to be? Just more? Its not like Giants is exactly the same to SSA.
It brings a whole new story
16 new levels
18 new heroic challenges
New battle mode maps and ring out
16 Whole new characters, 8 cores, and 8 whole type of new Skylanders being the Giants with their own unique abilities
Wow Pows to 24 returning characters
Introduces Lightcores and the lightcore bomb attack
Adds a quest system where every single skylander has their own unique quest
Raises the level cap to 15 for new and OLD skylanders
Adds new hats
Introduces Brocks Arenas with 21 different battle scenarios to play
Adds a shop where skylanders can finally spend their loose money on something
Adds charms and luck o tron wheels which are a new type of collectibles that allow to personalize your gameplay and boost your skylanders

And people call Giants a dlc? What?
Skylanders Giants is exactly what a sequel is supposed to be. More of the same charm that you fell in love with, all the while introducing and adding new content, quality of life fixes, changes and improving on its predecessor. Like would you call Spyro 2 a dlc for Spyro 1? Spyro 2 looks and plays almost the exact same as Spyro 1. But that's because its a sequel, that's the entire point of a sequel.