Some of my ideas

[Shroomerson]

Woohoo, another one!

Accessories

Just like in Superstar Saga, accessories return. Each accessory has their own equipment slot, much like Superstar Saga. Their effects can even be stacked with badges and other equipment. Unfortunately, some will only work on certain characters.

Mario
Firebrand Gloves- All fireball attacks have their damage increased
Peach Charm- A small bracelet with an image of Peach on it. Increases speed by 3.

Luigi
Excite Spring- All jumping attacks have their damage increased.
Gameboy Horror SP- Enemies have a better chance at dropping items.

Wario
Greed Wallet- Enemies have a better chance at dropping more coins.
Great Force- Doubles damage both given and received.

Waluigi
Cobalt Necktie- Stache increases by 5
Pinball Mini- A pocket version of Waluigi Pinball. Increases chances to block attacks.

Yoshi
Heavy Yoshi Eggs- All egg attacks have their damage increased
Running Boots- Increases speed by 3

Toad
Throwable Poison Mushrooms- All mushroom attacks have their damage increased
Golden Mushroom- Increases HP by 10

[Penguin4478]

Great Force on Wario seems a bit overscaled, and the damage up badge pretty much does the same thing on a lesser scale.
The cobalt necktie shoudl boost by 3 rather than 5 to keep on par with the peach charm and speed boots... Otherwise, I like this idea! It has similar ideas related to my passive effects suggestion

[Razz the Koopa]

While the Mario RPGs do have partners, having enemies as "pets" is very uncharacteristic of the Mario series. This idea sounds a lot like Dragon Warrior Monsters, Pokemon, or Keitai Denjuu Telefang.

Partners would be cool, but we currently don't have plans or time for them, sorry.

Actually, I can see where Shroomerson's going with this one. Its more comparable to Mario Party 3's Battle Mode, where you hire partners to join you and defeat your opponent.

If this idea were altered to be more comparable to Mario Party 3's Battle Mode Partners, I can see it being a very successful and Well-Ultilized feature that would set SMBO apart from other Mario MMO's.

[Shroomerson]

Kimi already said there's no plans for a party system.

Here's another idea:

Last Resort Special Attacks
These special attacks only become usable when you're at 5 HP or less. They are really powerful, but being at low HP will hurt.

Mario
Finale Fireball- A huge fireball is launched at the foe. May lower opponent's attack

Luigi
Finale Thunder- Lightning is launched at the foe. May lower opponent's defense.

Wario
Wario Waft Ultimate- Launches a huge stink at everyone within a 3 space radius.

Waluigi
WALUIGI TIME- Instakills the opponent ONLY if it's an enemy. Has no effect on players.

Yoshi
Egg-plosion- Lays an egg bomb where you are standing. Explodes after three seconds, damaging whoever is in a 5 space radius.

Toad
"Sorry, I'm in another castle!"- Warps you to a connecting map.

[Penguin4478]

Unless all of these have the power to 1-hit NPCs, they really can't be used for anything other than PvP, except for Waluigi's if his attack has more than 1-2 range. This is simply because so far there aren't any hotkeys and spending time to initiate the special attack in a non-turnbased battle could result in, ironically, your own death.

[Razz the Koopa]

If each attack has X Tile Radius thats Greater than 1, then they can be used from a Choke Point with no risk to the player. Like against Elite Shy Guys in General Guys Room, or if Tutankoopa is trapped on his ledge. The only issue then would be if the Attacks cost HP to use.

[Shroomerson]

...

Crossover Station

No, this does not mean other Nintendo franchises are coming in. This is the name of a small area where both the Mushroom and Beanbean Kingdoms connect. The small town is located south of the Beanbean entrance pipe in Shy Guy Caves. When you get to the entrance, two Whomp guards will block the way in...

Whomp 1: "Whoa there buddy, you want to come in this area? I see you're not a generic enemy species, so you better get lost!"

Whomp 2: "However, toughness is a requirement for enemies, and you look like you have potential. Tell ya what, come see us when you're about Level 50 or so, and we'll let you in."

The place is home to many Mario enemies of all kinds. They won't fight you, they are all friendly and will talk to you.

The Crossover Station is the lead trade center for imports and exports through both kingdoms, and it looks almost like an airport. Lots of funny dialogue comes from most NPCs...

Goomba: I'm getting a DVD import of "The Grodus Chronicles" from the Beanbean Kingdom soon. I wish it would arrive sooner!

Blooper: I have a cousin that fell in a volcano, turning him orange. Because of that, he says he'll never travel with guys in green clothes ever again.
(Referencing Blooey during Luigi's journey in PM:TTYD)

Koopa Troopa: I like staying at hotels sometimes, but the "Cherbil's Delight Inc." hotel has the worst record ever!
(Look at the first letters in the hotel name for a reference)

Other than that, many others will trade rare items for some hard-to-come-by items. I can't think of any specifics, but I'll think of some.

[Shroomerson]

I have a few misc. NPC dialogue ideas:

Mushroom Town:
Toad: This town has strong connections with Toad Town. We usually get imports and exports from the place.
Toad: A friend of mine from back home sent this "Beetle Mania" game to me. It's quite addicting.

Koopa Village:
Koopa: Apparently Yoshis can cause dust clouds when eating a Koopa with a yellow shell. I don't want to be around to know if it's true or not!
Koopa: I'm afraid of water, but I live near it. Weird, huh?

Kinopio Village:
Toad: Dispite not many people coming here, I sometimes enjoy the piece and quiet!
Toad: I got an autograph from Zip Toad back in Rougeport, and now it's my most prized possession!

Mushroom Kingdom:
Goomba: I want to be a Spiky Goomba someday, but I just need the green hat.
Koopa: I'm a big fan of Professor Kolorado, and I wish to join one of his expeditions someday!
Toad: I miss hosting Mario Parties...

Beanbean Castle Town
Beanish: Yoshi Theater is my favorite place. I just watched the movie "Mario Story" there yesterday!
Beanish: *hic* I think I drank too much Chuckola Cola. *hic*
Beanish: The people at the Oho Oasis look and speak strange. Luckily, I'm not one of them!

[Shroomerson]

Coin Challenges
Coin Guy: "Oh dear, seems I have lost some of my prized coins. Can you please help me find them? I seem to have lost 8 Red Coins and 8 Blue Coins in each area. If you bring me all 8 Red or Blue Coins from an area, I'll have a special item or badge in store for you."

Basically, there are 8 Red and Blue coins hidden at each main area (Mushroom Plains, Koopa Islands, Flower Hills, etc.) and if you bring Coin Guy all 8 Red Coins and/or Blue coins from an area, he'll reward you with a rare item or badge.

I can't think of good rewards for this though.

[Razz the Koopa]

I say yes to Red Coins. Blue Coins...Maybe... But its definitely a good idea.

[Shroomerson]

 

Attributes

There would be a special house that gives you 2 of certain traits for a good amount of money. Every time you pay the amount, the shopkeeper gives you 2 special traits at random. If you don't like your trait combination, you can pay the shopkeeper again to randomize your traits again.

Here's some example traits (there is A LOT more than this):

FP Saver- Makes you sometimes use an attacking special without wasting any FP. Does not work with stat boosting and healing specials.

Enemy Chainer- Attack rises the more you keep killing the same type of enemy. Resets if you attack another player or a different enemy.

Crowd Brawler- If swarmed by multiple enemies, your attacks might hit another adjacent enemy (not just the one you're attacking)

Epic Finisher- If the enemy is at 1/4th of it's maximum health, your critical hit chance doubles for that enemy.

Bodybuilder- Sometimes when you defeat an enemy, you get 10 extra Experience Points

[Penguin4478]

I think bodybuilder should give you more EXP based off of a % of the enemy's normal exp. Otherwise, the other suggestions seem pretty good.

[Shroomerson]

More traits!

Buddy Booster- Slightly increases stats of members in your party. Doesn't work in PvP areas (Assuming you joined or formed one).

Muscle Builder- Increases weapon damage, but lowers special attack damage.

Spellcaster- Opposite of Muscle Builder.

Taste Tester- Get a 2 point increase when using food items (Ex: Mushrooms now heal 7 instead of 5)

Food Prober- Occasionally avoids negative effects of food items.

Sharp Shooter- Increases long range weapon damage (Only useful for Wario, Waluigi, and Toad right now).

[Shroomerson]

The Gauntlet

Works like in BiS, but there are "sets" instead. In each set, you fight some enemies in order with a harder version of one of the many bosses at the end. You go to a resting room in between each battle. Beating a set gets you prizes. Here's the sets:

Set 1: Mushroom Insanity!
Battle 1: 3 Shrooblet X
Battle 2: 2 Goomba X, 1 Koopa Troopa X
Battle 3: 2 Koopa Troopa X, 1 Red Koopa Troopa X
Battle 4: 1 Shrooblet X, 1 Goomba X, 1 Koopa Troopa X, 1 Red Koopa Troopa X
Battle 5: BOSS- Lakitu X
Prizes: Cards of the X enemies in the set, set amount of coins, set amount of Star Pieces (not DSP), access to Set 2

Set 2: Island Melee!
Battle 1: 2 Borp X, 1 Red Gnarantula X
Battle 2: 1 Borp X, 1 Red Gnarantula X, 1 Koopa Troopa (shades) X
Battle 3: 2 Koopa Troopa (shades) X, 2 Piranha Plant X
Battle 4: 3 Drillbit Crab X
Battle 5: BOSS- Green Coconutter X
Prizes: Cards of the X enemies in the set, set amount of coins, 30 Good Apples, access to set 3

Set 3: Brawl in the desert!
Battle 1: 3 Pokey X
Battle 2: 2 Dry Bones X, 1 Pokey X
Battle 3: 3 Bob-omb X, 1 Dry Bones X
Battle 4: BOSS- Tutankoopa X
Prizes: Cards of the X enemies in the set, set amount of coins, Bronze Gauntlet Trophy, access to set 4

Set 4: Clash of the flowers and sewers!
Battle 1: 2 Gloomba X, 2 Spiny X
Battle 2: 2 Paratroopa X, 2 Underground Koopa X
Battle 3: 2 Shy Guy X, 2 Underground Bob-omb X
Battle 4: BOSS- Runaway Chain Chomp X
Prizes: Cards of the X enemies in the set, set amount of coins, 10 Melons, access to set 5

Set 5: Mushroom Kingdom Royale!
Battle 1: 2 Pipe Lakitu X, 2 Blue Koopa X
Battle 2: 2 Blue Koopa X, 1 Blue Paratroopa X, 1 Pipe Lakitu X
Battle 3: 2 Hammer Bro X, 1 Pipe Lakitu X
Battle 4: 3 Red Coconutter X
Battle 5: BOSS- Kamek X
Prizes: Cards of the X enemies in the set, set amount of coins, access to set 6

Set 6: Underground Fight!
Battle 1: 2 Underground Spiny X, 1 Fishin' Lakitu X
Battle 2: 3 Underground Shy Guy X, 1 Fishin' Lakitu X
Battle 3: 3 Elite Shy Guy X
Battle 4: BOSS- General Shy Guy X
Prizes: Cards of the X enemies in the set, set amount of coins, Silver Gauntlet Trophy, access to set 7

Set 7: Beanbean Boys!
Battle 1: 2 Beanie X, 2 Spiny X
Battle 2: 2 Beanie X, 1 Troopea X
Battle 3: 3 Parabeanie X, 1 Sworm X
Battle 4: 2 Sworm X, 1 Tanoomba X, 1 Chuck Guy X
Battle 5: 2 Tanoomba X, 1 Chuck Guy X, 1 Paratroopea X
Battle 6: BOSS- Poison Dry Bones X
Prizes: Cards of the X enemies in the set, set amount of coins, access to set 8

Set 8: Rockade's Revenge
Battle 1: 6 Angry Rockade (rocks attacking AAAAAAH!)
Battle 2: BOSS- No-Joke Rockade
Prizes: Cards of the enemies in the set, set amount of coins, access to champion

Set 9: Champion Match!
Battle X: (can't think of enemy)
Prizes: Card of the champion, set amount of coins, Gold Gauntlet Trophy

[Shroomerson]

Guess who's been playing Sticker Star?

Glitter Powder: Really pretty powder! Might have a use somewhere...

Flashy Powder: Very brightening powder that's hard to look at. Might have a use somewhere...

Recipes:

Shiny Shell (Glitter Powder + Koopa Shell): A shell that looks like it's been cleaned recently. Might sell for a good amount of coins.

Flashy Shell (Flashy Powder + Shiny Shell): A shell that is very pretty to look at. Sells for a lot of coins!

Shiny Mushroom (Glitter Powder + Mushroom): A very glistening mushroom. Heals 5 HP and 20 SP.

Shiny Super (Glitter Powder + Super Shroom): A very glistening super mushroom. Heals 10 HP and 20 SP.

Shiny Ultra (Glitter Powder + Ultra Shroom): A very glistening ultra mushroom. Heals 20 HP and 20 SP.

Flashy Mushroom (Flashy Powder + Mushroom): A very bright mushroom. Heals 5 HP and 30 SP.

Flashy Super (Flashy Powder + Super Shroom): A very bright super mushroom. Heals 10 HP and 30 SP.

Flashy Ultra (Flashy Powder + Ultra Shroom): A very bright ultra mushroom. Heals 20 HP and 30 SP.