If you're going to have a dot between art and online, you're going to need a dot between block and art, like so: ブロック・アート・オンライン
Just realized you're going after the style of Sword Art Online.
I have no idea if this project is even remotely related to Japan, but seeing as the title is in katakana, I'll assume it is and offer my help with anything related to Japanese culture/language. Currently living in Japan for a year with my mom's side of the family entirely Japanese, so you know I'm not a weeaboo with a false sense of Japanese culture.