This page. It promises a lot, but I can't find further information.
Apparently the first rule of Arduino Cloud Games is that Arduino does not talk about Arduino Cloud Games
I asked people on Arduino and they said there's definitely something coming up on Monday. Probably a live stream.
Ah, you found the teaser page! We've just announced it on the forums (going out on social media later), so you guys can now start submitting project ideas for the Cloud Games initiative ahead of the crowds! Join the Arduino Cloud Games!