Not looked at Gemini and if it is just for the US only then it's not for me.
Yup, looks like it's for US only and not even for all the states:
AVAILABLE STATES
Gemini is available and open for trading in the following states:
California, Colorado, Delaware, Florida, Idaho, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Mexico, New York, North Carolina, Ohio, Rhode Island, South Carolina, Tennessee, Utah, Vermont, Washington D.C., Wyoming.
Update October 7, 2015: Illinois is now available.
--------------------------------------------------------------------------------
PENDING STATES
Gemini is working with regulators to become operational in the following states as soon as possible (and we will update this list accordingly):
Alabama, Alaska, Arizona, Arkansas, Connecticut, Georgia, Hawaii, Illinois, Iowa, Maine, Massachusetts, Nebraska, Nevada, New Jersey, North Dakota, Oklahoma, Oregon, Pennsylvania, South Dakota, Texas, Virginia, Washington, West Virginia, Wisconsin.
Likely they will expand to other countries (at least EU). Bit shame EU clients are not accepted from the start, I don't think there are any serious regulatory obstacles preventing it.