Well then, I just find this simply an awesome idea indeed, and I hope I'm not too late in contributing to this thread.
In regards to monsters, Novacat
made some excellent versions of the creatures in the mario universe I feel. I would like to see these guys get used, even if they're not official monsters.Novacat's Nintendo Monsters
In regards to races, maybe Half Orc could actually = Kong's? As Halforcs do have the whole ability to deliver one deadly punch. Otherwise, I'm sure some other strong race could possible fit in there, maybe.
As for Toadstool race, ye could consider the Wilden Playtest race, they be fairy plant people. If ye have Insider, or a friend does, ye could make use of it, here's the link: Wilden Playtest
I also support the idea of Yoshi's being half elves, Bomb-Omb's = Bladelings, and Kobolds = Goombas.
Devas=Ancients (Merlin People)
Also to maybe help add to that galaxy idea, perhaps it can be thought of as the "planar" equivalent it is in 4th edition. Also that, 21st-30th level, space faring adventures will be commonplace, maybe they'll even face a villain from the Kirby series if ye desired.
So, 1-10th, mushroom kingdom, Yoshi's Island perhaps,
11th-20th, the other lands of course, bean realm, perhaps sunshine place as well.
21-30th, entire Super Mario Galaxies
Also, ye could implement idea such as there being a galactic tournament, where the greatest warriors gather, called "Super Smash Bros". Also, Yoshi races could be doable as well.
I'm glad such a thread is made, I hope I was some help in some form. I was thinking of a different approach to this universe, the idea of a Justice League for Nintendo, a JLN, or as I'd call it, "Nintendo All Stars". If ye do use that idea, perhaps the PC's would get hired by the "All Stars" at around 11th-20th level or so.
Oh I'm aware you're using 4th edition and all, but there was also a D20 version of this game made prior, "Mario D20" it was called, here's the site to where ye can find it. It might help ye with some ideas for things, and it has some other minor stuff too.Mario D20
EDIT: Also, here's a Donkey Kong someone created over on "some other forum", by the name of "LogicNiinja". As thus it is not my creation, this was shown to me by a friend of mine in fact. Donkey Kong
Level 11 Solo Brute
Initiative: +10 ------ Senses: Perception +8; low-light vision
HP 428; Bloodied 214
AC 25; Fortitude 24, Reflex 24, Will 22
Saving Throws +5
Action Points 2
Kong Smash (standard; at-will)
--Reach 2; +14 vs. AC; 1d6+4 damage and knock prone.
Kong Fury (standard; at-will)
--Donkey Kong makes two Kong Smash attacks. These can be against the same or two different targets.
Barrel Toss (standard; at-will)
Donkey Kong seizes a barrel or other suitable object and hurls it at the target. Ranged 5/10; +12 vs. Reflex; 2d6+6 and knock prone. The sq -Miss: the square behind the target becomes difficult terrain.
Ground Pound(standard; encounter; recharge 6)
--Close Burst 2; +12 vs. Fort; 2d8+6 damage and knock prone.
Monkeying Around (standard; encounter; recharge 5 6)
Donkey Kong jumps 4 squares, and can end this movement in an enemy's square. If he does, he makes a Kong Smash attack against that enemy and gainst Combat Advantage for that attack. He can then either slide the enemy 1 and end his movement, or jump 4 more squares, but must end this movement in an unoccupied square.
-Critical hit: If Donkey Kong gets a critical hit while using this power, he immediately recovers and uses this power again rather than completing his movement. When using this power, Donkey Kong scores critical hits on a roll of 19 or 20.
Donkey Punch (immediate reaction, when an enemy moves to a position where it flanks Donkey Kong; at-will)
--Donkey Kong attacks the enemy with a Kong Smash attack, except instead of knocking it prone he pushes it 1 square.
Skills: Athletics +20; Acrobatics +20