with pdfcube version in my Debian Lenny (0.0.2-3+b3), you can only use 'c' to move to the next page with a transition. With space you get no effects. I figure this has changed in 0.0.3 that is used in this article.
pdfcube is indeed a nice little toy at this stage. KeyJNote / Impressive is already an interesting application that may even be usable enough for real-life presentations.