1. Project M is 100% playable on an unmodded Wii or Wii U2. It is made with the competitive scene in mind--players who liked Melee.
But the ideology is that Melee was fun for everyone and no one working on this forgot it is a mascot fighter series.Sorry to go bold right there but I wanted to clear up two misconceptions that turn some people away from Project M before anything else.
So if you haven't heard about it, Project M is a big mod that changes Brawl into a faster-paced and more balanced game that plays like Melee. Every character returning from Melee uses their SSBM properties as a floor but no one is exempt from changes. Even Fox or Falco. The Brawl newcomers have new toys, different toys, and some mechanics that have never been seen in Smash Bros. before. Almost every character feels stronger in some respect, especially the ones who really needed the buffs, like Samus, Link, Bowser or Zelda. It's a lot of fun.
And if the main draw to Smash Bros. to you is the same as for me--"I can make Mario fight Link!" then Project M should be up your alley from all the new love letters to the characters' original games, and stuff like that.
This is a playable alternate costume for Peach.
Dry Bowser and Dry Giga Bowser. They went to the trouble to give Giga Bowser alternate colors matching Bowser's color changes including this one for his model change.
These guys are back and do not replace anyone already in Brawl. The entire cast plus Mewtwo and Roy are fully playable as of 3.0 (except Red the Pokémon Trainer, whose Pokémon are now completely independent fighters).
Ness's smash up-taunt.
Wario's moveset and animations are the Wario Land-inspired attacks that even a 'Ware fan like me thinks he obviously should have had to begin with.
It's all a very professional labor of love. If you've got an SD card 2GB or smaller that you're not using, give it a whirl. You won't regret it.