Playable Bunston, Moe, Starly, so as to support 4 players
Multiplayer: simple as picking up multiple controllers
10 worlds, plus a hidden 11th after 100%ing the game
More minigames, more creatively named
Some new characters
The Trio is the final boss instead of a nutso space pirate who eats Bunston
Each world should have 6 stages with 4 secret stages hidden until you complete certain tasks
Better postgame where you solve a mystery on who stole Herman's pet Coddies
Cutscenes are styled like an animated manga (just like last time), although with more poses for each character
The Trio keeps their leitmotif, although it's remixed slightly
Said leitmotif is used a bit in both phases of the final battle
The Trio fuses after phase 1 is done, and should stay that way for phase 2
Difficulty selection
Easy Mode gives you 20 hearts instead of 10, infinite spins without the worry for dizzy lockdown, enemies and bosses are easier to defeat
Hard Mode: 10 hearts, can only spin 3 times and then dizzy lockdown, enemies and bosses are average difficulty
New characters:
Bosses 2-8
Kid Lobber, Old Man Lobber's protege and successor
Mr. Moby, a whale so big, he's his own world
Sid Small, a large turtle
Perry Keet, the bird on Sid's head
Morris, a winged pig who's Starly's new boyfriend
Minigames:
It's About Time, in which you rearrange clocks to the specified time (only 720 possible combinations)
Number-Up!, in which you count a kind of mook (varies each time you play)
Pachinko Spree, in which there are coins scattered throughout the pachinko machine (the most coins wins)
Character Quiz, in which you have to correctly guess 10 silhouettes (should be relatively simple)
Grind!, in which you are awarded points for grinding crazy tricks (the fancier, the better)
Breakaway, in which you spin through the blocks by mashing the A button (the most blocks spun through wins)
Bomb Toss, in which you play Hot Potato with a bomb (linger too long or just plain be unlucky and the results will not be pretty)
Riceball and Dumpling, in which you make riceballs (onigiri) and dumplings (takoyaki) for characters who request one of the two
New Postgame: The Coddie Case
Who stole Herman's precious Coddies? Traverse across the whole game thus far and find out who could've done such a heinous thing!
You should also be able to unlock songs from the last game. You'll be able to find most of them throughout the game, but once you reach the postgame, you'll end up finding the final one!
The Terrible Trio should have their leitmotif appear in bits and pieces for the last world, Janken Junction. This includes both phases of the final battle.