try these challenges.

[Croyles]

Mario cart with two people (the one where two people can control one cart) The person controlling sits on a spinnable desk chair. If your cart hits a banana peel, the other person spins you around and you have to try and carry on playing (somehow NOT getting tangled up with the controller cord). If you shrink, then the second person lowers your chair. If you fall off the track, the second person tilts the chair forward until you hear a satisfying 'thunk'.
If you swap drivers, you have to quickly sit down instead of your partner.
Great fun!