There was, but it was...sort of a puzzle platformer? And you could never be DK. A game where you play as both Mario and DK, mixing gameplay elements from both series, that'd be interesting.

yes.now i remember,it was a 2d platformer for gba.and dk was antagonist!!

Pikmin

Mario Card Battle game on...

=P

I'd actually really like a crossover 2d game between Mario, Donkey Kong, and a cartoony Zelda (that way they all have the same or very similar art styles and it works). It would be pretty epic if the game covered various parts of all three worlds (and they could even explain how the Mushroom Kingdom and Donkey Kong Island could exist in the same world, just far away, as Hyrule).

Maybe the land of Hyrule and the lands surrounding it are far away from the Mushroom Kingdom or are on a different continent altogether. Maybe Hylia even blocked it off from the rest of the world for some reason. The Donkey kong islands being seperated could work even more since they are islands and could be out in the middle of the ocean somewhere isolated.

I think having one where the heroes of those games unite to face a combined enemy force of all the main enemies from each of those universes could be epic. Just imagine how hillarious the dialogue could be between those enemies:

Ganondorf: "So we are in agreeance? We shall collect and combine the powers of the Triforce, the star rod, and the... what did you call it again?"

K. Rool: "The GOLDEN BANANA! How many times do I have to spell it out for you? I suppose I shouldn't expect you to be intelligent seeing as you were a THIEF!"

Ganondorf: "Say that again and I will trap you in the dark world and you will spend eternity looking like a bunny!"

Bowser: "Would you two SHUT UP!? I'm trying to daydream about how Princess Peach will adore me if I I possess the power of all three of these items!"

K. Rool: "Don't you mean, when WE possess that power?"

Bowser: "Oh yes... of course! HAHAHAHA that's what I meant... *pss Magikoopa... remind me not to protect this lizard and this other guy who keeps being reborn (or so he claims...) and to allow the red plumber and the green stache to bounce them while I collect these three items*

Magikoopa: "Yes my lord Bowser."

Ganondorf: "What was that? What did you say?"

Bowser: "Oh... we were just talking about... about... some redecoration ideas we had for my latest castle..." *cough*

Ganondorf: "You and your trivial things!"

K. Rool: "So... what shall we call this item that is created by merging the relics?"

*After much debate and arguing and various lizards, goombas, and flame spitting crabs were thrown at each other, they agreed to call the grand item the....
Star Banana of Triforce!

-The end

___________________________________________________
See people? I had a LOT of fun typing that up and think it's amusing lol I would love to play a game like this where it had the humor of the paper mario style games with all three of these guys in one game!

I like it. Not sure why Nintendo hasn't tried some sort of RTS before with Mario. Might help the genre as a whole. I know my first RPG was Super Mario RPG, and that got me into RPGs, I bet this would get a lot of people into RTS games as well. The Space Marines, Space Animals, and Elves could be from two other alien races the evil aliens conquered, and Mario helps save their worlds so they join him. Space Marines are your typical military society, Space Animals are a beast race, and Elves are a race of beings close to nature. They'd all fit into the Mario universe well enough, especially after Galaxy.

completely forgot dat

Huh, so basically Kingdom Hearts with Nintendo? Nintendo Hearts? Shut up and take my money!

Wait, why 2D? Zelda has only been 2D in Zelda II, and that didn't turn out too well. Unless you mean overhead, but Mario and DK have never been overhead 2D either. I think it should be 3D.

Hey, I mean, it could happen. Nintendo did say they wanted to make simple smart phone games to introduce people to their characters. I'd bet they'd do it for 3DS though, with actual collectible cards, and they'd be AR cards. Remember the AR cards? The 3DS came with them and then Nintendo never did anything with them aside from a little thing with Kid Icarus? Do that with the Mario card battle! I feel like that could be huge! It'd be like Yugioh in real life! Come to think of it, why hasn't something like that happened yet?

A game where you play as a Goomba... would simply be the greatest game of all time.