I would build a robot as a Drone that shoots Nerf harmless arrows! You could then have fun battles between friends.
By myriaddev
Other robots from Synthiam community

Williamk's Inmoov
Humble beginnings. Havent gotten beyond testing the movement of motorized pieces as of yet but everything is basically...

Smitheken's My Track Driven Video Bot
I have used the track and servos as the base with the ez-controller and a wireless Ip camera, works good. I used a...
Intellamicrorobotics's Meet @Arti_Robot
My robot friend aRTi began from about 20lbs of PLA. aRTi is a work in progress. I built aRTi to learn. There is a future...