Try and go for a shorter snappier name 
May be 3 letter domain like BTC dot com or net, even org would be more catchy, brandable and attractive,but ONLINEBITCOINGAMES.COM will be very good for SEO and professional webmasters will find the way to rank the domain(website) in first page of google or bing etc...
Keyword domains are and always will be wanted(may be the word wanted isn´t correct, but you will understand me
. I just hope that bitcoin games get more popularity... 
Regards:
By the way, what about BITCOINYE.COM ?
Thanks for your comments. I just wanted to say that 3 letter domains are perfect for branding, but keyword domains are very important for SEO.
That´s why the domain name onlinefreegames(com) was sold for 90000 usd. I have a dream that bitcoin games get more popular
Regards.
ONLINEBITCOINGAMES.COM BITCOINYE.COM