A snowball fight dame on the Ethereum Blockchain
Website to PLAY (you neet to connect your Metamask to Ropsten Testnet!): https://smokincaterpillar.github.io/Snowballs/
I talked a bit about this project at the PyData Berin 2018 conference, you can find a pdf version of the slides in this repository as well: https://github.com/SmokinCaterpillar/Snowballs/blob/master/pydata_berlin_2018_slides.pdf