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 ?