Summary: The 8 -n-1 parts are pre-formed and are "interchangeable" for Wii remotes with and/or without silicone cover. However, the gaming extras were manufactured for the 'add-on' adapter of Wii remote plus motion, thus when playing with the new "built-in" motion plus remotes the gaming pieces look bad because of the "free space" where the adapter would typically be.
Summary: I got this kit for my 4 year old who loves Wii Resort Sports. He can get the Wii controller in these add ones himself so it's very easy to set up and use. He loves the sword the best and it makes some of the games easier for him to play having the realistic add on.