I bought a bundle of 19 used SWAP force figures from eBay.
3 of them are magic items: Groove Machine, Platinium Sheep and Sheep Wreck Island.
So beside the face that I know have enough presents for my 6yo son until he goes to college, What are those magic items actually for? I need to put them with the regular SWAP force figures, but then what?
The sheep turns the figure into a... sheep for several seconds.
The groove machine just follows me around.
The wreck island is doing something I couldn't really understand.
What you've noted is pretty much it, the magic items just do small things like having a quirky effect, following your character around, some do damage to enemies on screen one per level, some give you more gems.... The Groove Machine makes nearby enemies dance for a bit, as well as following you around.
Sheep Wreck Island is a type of Magic Item known as a Level Pack - when you use this on the portal in the hub area for the first time it unlocks a new, extra, level of the same name (I forget where on the hub area you find these levels to play them). I believe it also does damage to enemies on screen if you place it down during a level.