You don't need to worry about Japanese developers when it comes to creating an insane, over-the-top frenzy on the screen. It's in their veins.
Just think about the superb 60 frames per sec action in Bayonetta or having twelve characters on the screen all at once in Guardian Heroes (thank you Sega Saturn), few things are cooler than Japanese video games with their crazy amounts of chaos.
Bangai-O Spirits
Blowing up everything on the screen at once continously is not an issue in Treasure's 2008 mecha shooter for the Nintendo DS.
Ultimate Marvel vs. Capcom 3
The combat animations, crazy combos and called-in assists create ridiculously cool chaoson screen in Capcom's crossover fighting game.
Gungrave
A superb third person shooter for the PlayStation 2 in which we control an undead protagonist going after those who killed him.
ESPGaluda
ESPGaluda is one of the many crazy manic shooters from Cave. The arrange mode that changes gameplay rules was added to the PlayStation 2 port in 2004, making it much harder and chaotic.
Crazy Taxi
There are no rules in Sega's arcade racer, which promotes taxi driving to one of the most enjoyable jobs in the world.
Mushihime-sama Futari
Another bullet hell shooter from Cave, released in 2006, and with its ultra difficulty mode, it's also among the hardest.
Guardian Heroes
One of the crown jewels of the beat 'em up genre and the Sega Saturn. Six players could play simultaneously making it up to twelve on screen at once, creating a hell of a mess.
Bayonetta
Platinum Games' fast paced third person action game tops most of the titles of this genre with its complex, awesome looking combat system and with its difficulty done right. Also, it's a great thing that Platinum Games stayed on this route with Vanquish and Metal Gear Rising. Fingers crossed for Bayonetta 2.
DoDonPachi Dai Ou Jou
The fourth entry in the DoDonPachi series from Cave, this bullet hell shooter is just insane-super-crazy with impossible situations.
R-Type III
Released in 1993 for the SNES, Irem's shooter proved that horizontal scrolling shooters can also be insanely hard and awesome with fast paced action messing up the screen.
Make sure to add your picks in the comments with visuals, focusing on the most insanely chaotic and crazy gameplay moments in Japanese video games.
sources: Nereid0, JonGodGames, SEGA, Capcom, CAVE, Guardian Heroes Remix, Bayonetta Wiki, Nautth, Naka Teleeli