It's downloadable from the game's page.
-Has the opening cutscene, an endless stage, an option to replay the character turorials and a 2-player mode (haven't tried it). The opening cutscene is fully voice-acted but the animation isn't lip-synched at all.
-The microgame stage is endless, pure survival (no boss games). Difficulty increases after a dozen microgames.
-You start with Wario and get Cricket and 18-Volt after clearing three micro games. When you get a game over, you unlock Mona, then Kat & Ana, then Orbulon. When you unlock everyone you get the option of either playing as a 3-man team or with every characters.
-You can control your character between microgames (good for fidjetters)
Other stuff I noticed from the splash screens:
-There'll be a lot of Mega Party Games-style multiplayer modes.
-The achievement and currency systems from Gold are back
-You can give objects to characters (?)