... perhaps one of the craziest crossover games ever... that is perhaps the best way to describe Hyperdimension Neptunia.
The game is a Japanese RPG title that has been available in Japan for a little while now; the game features characters and mascotts from a variety of Japanese game companies including Compile Heart, NIS America, GUST, Idea Factory, and Sega. These include summon attacks that feature the likes of Alex Kidd and Space Harrier. The game is set in the imaginary world of Gameindustri and requires the player to assist the four console Goddesses who protect the world from the attacks of the evil Arfoire. To answer your question: yes it is as weird and crazy as it sounds.
What is even stranger, perhaps, is that the game is going to see a North America release. Hyperdimension Neptunia is scheduled for release in February here in the states and NIS America has released a new, English trailer for the game to prove it. You can view the trailer and all of its horrible English voice-overs below... don’t worry though, the full Japanese language track is reported to be included in the game.