At the end of the features section, it reads that "brand-new dungeons" and "an Arena mode" will "add exciting new dimensions to this timeless classic." Is this the two-player mode that we're all in the dark about? Sounds like it to us, meaning Chrono Trigger could allow for co-operative play in these new dungeons, as well as some kind of versus mechanic in this Arena mode. We might be reaching a bit, though, with the reality of it most likely being the new dungeons are only accessible from the single-player campaign and the Arena mode will let you and a friend do a boss rush or something.
Gallery: Chrono Trigger