My ideal Mario All-Stars 2 would have all the main 3D games including 3D Land remade using the old code when applicable but new graphics (sans Odyssey and 3D World, the prior of which is excluded and the latter is just a port), as well as direct ports of every main 2D game (sans Wario Land, Yoshi's Island, the Maker games and NSMBU) with traditional emulator features (save states, rewind, maybe a challenge mode and achievements).
Also, there'd be extra characters, Sonic 2 and Knuckles style, for certain games, every game would have Luigi playable in some form, and Peach for every 2D game except Land 1 and 2, which get Daisy.
There'd also be DK in SMB1 and Lost Levels, who is MUCH slower but can also Goomba stomp on any enemy, Link in Mario 3 with his SMM2 moveset, Wario in Mario Land 2 with the shoulder bash, Pikachu in Mario 64 with a unique moveset of his own and his classic "fat" design, and possibly Sonic in Mario World if Sega are on board.
SMB3's e-Reader levels would be included.
