Probably not. CloudFlare only makes sense for websites because they can cache content, resulting in a more responsive website and better user experience. Games can't be cached, so whatever protections they can offer will come at a downside of having to use CloudFlare servers instead of servers designed to host games.
Also, DDoS isn't a big deal for most games. (MMOs, yes, but not most games.) If a gameserver is DDoSed, then a few dozen or a few hundred people are going to be unhappy. Whereas if a website is DDoSed, then tens of thousands of people will be unhappy at a minimum. Since most games aren't really affected by DDoS, it doesn't make much business sense for CloudFlare to try to offer gameserver protection. The market probably isn't big enough to warrant diverting CloudFlare time and resources.
Few dozen or few hundred? This isn't the 90s, games are played by millions of people daily. More than tens of thousands of people are effected by someone taking down, say, LoL servers with a DDoS.
you're forgetting that a lot of games use the individual server model. for example battlefield 4 has 70 player max on any given server. meaning a DDOS will only cause problems for that many
In those cases, there is usually a non-player server that can be targeted.. Also, there is absolutely nothing stopping this kind of attack from hitting multiple servers; the only limit is the total bandwidth.
Also, DDoS isn't a big deal for most games. (MMOs, yes, but not most games.) If a gameserver is DDoSed, then a few dozen or a few hundred people are going to be unhappy. Whereas if a website is DDoSed, then tens of thousands of people will be unhappy at a minimum. Since most games aren't really affected by DDoS, it doesn't make much business sense for CloudFlare to try to offer gameserver protection. The market probably isn't big enough to warrant diverting CloudFlare time and resources.