A splash end page is a splash page for a website that has no apparent way to enter into the main part of the site. Comes from the phrases Splashpage and Dead end
"I went to your website, but it just opened up a splash end page."
"Haha. Are you stupid or something? All you need to do to get in is double right click the top left corner of the screen and type in the year that my cousin Frank was born in, then navigate through the maze and save the princess. Duh."