Spider web game. Just use painter's tape to make the web and have the kids throw wads of paper at it to see if they can get it to stick.
This would be hysterical!!
Send a box full of balloons with notes/money inside each one. Won't weigh much to ship! My sister did this for my son's 11th birthday. BEST. AUNT. EVER!!!!
Ping Pong/Tissue Box Game!