I don't think a TCG would be a good idea in the long run. Remember, they would have to include ALL of Nintendo's history and they would have to be creative in what each card does.
However, I would be fine with replacing the stickers with cards.
DURO! MONSUTAA CAADO!
Even Nintendo doesn't include ALL of Nintendo's history. They wouldn't have to and it still could be a really engaging game.
i actually did a tcg based on smash like 3 years ago
Same for me. I still have the text files of my TCG rules and all the changes and additions I came up to make it as fluid, fun, and similar to Smash Bros. as I could. Mine works on two very distinct elements.
1 - Characters are pretty much decks. (Mario Deck, Luigi Deck, Kirby Deck, etc.) Now to avoid the stress of having to collect tons and tons of cards just to put together a remotely decent character deck, there are plenty of "Global" cards that can fit in all character cards. You would need at least 1 card to make a deck (called the Starter Melee card), and you can't include cards belonging to other characters, but there would be plenty of globals to make things easier.
2 - There are actually TWO decks in my game: The "Melee Deck" and the "Supply Deck".
The Melee Deck is the important deck and has all the means to successfully combat the opponent. Each card is broken up into subsets:
Starter Card - The one card all Melee Decks need. Defines the type of deck it is and is pulled out of the deck from the start of the game. Provides the stats of the character such as Weight, Jump, Speed, and PP (Power Points).
Ground Card - A basic Melee card. The higher the character's Speed, the more Ground Cards can be played in a single turn. Attacks from these cards might cost PP to use, but those replenish at the start of your next turn.
Air Cards - Tend to be better than Ground Cards, but less varied as well. The higher the character's Jump, the more Air Cards can be played.
Throw Cards - Tend to be pretty inexpensive and easy to use, but often don't do well to KO or inflict great damage. More of a "setup" kind of card
SMASH Cards - The power-players of the deck, these tend to be pretty PP heavy but are also the best means to score that finishing blow and win stocks.
Special Cards - The tricksters of the deck, these cards are more reliant on special effects that can turn things around for players when used properly.
Global Cards - Not necessarily a subset, but these relatively fit into any kind of deck so players have an easier time building a good deck.
Taunt Cards - a recent addition I came up with, they're basically Supply Cards that go into the Melee Deck and support the player. A prime example: Captain Falcon gets a card called "Show Me Your Moves!" and the opponent shows his hand. =P
The nice thing about how these cards are made is that I've avoided limited creativity by how I choose to create a card. Let's say I want to do something with Falco's Neutral B - his blaster. I don't just need to have a card called "Falco: Blaster". All Melee Cards are
sub-named meaning all of Falco's cards are sub-named
"Falco Melee Card". The actual name of the card though can be just about anything:
Falco's Blaster
Blaster Barrage
Blaster Combo
Falco's Stun Shot
Now the "Supply Deck" consists of various beneficial cards to further boost a player's chances of winning. These are as followed:
Item Cards - They're broken up into three subsets: Basic Items, Throwing Items, and Equip Items. Pretty self-explanatory. Items can be used during your turn OR by "containing" an item (playing face-down) can be used during an opponent's turn. (Yes, containing as in "Container" ;D)
Trophy Cards - Used only during your turn, they have various effects of a usually wide range. Can either be used once then discarded or set for multiple turns.
Event Cards - Cards that specifically support Melee Cards directly, attaching to them and improving their usefulness.
Now how it's generally played....
Each turn you can choose to draw from one deck or the other, depending on whether you need to bolster your fighting techniques or improve your overall situation.
The actual method of winning was devised to work extremely similar to an actual game of Smash. All characters have weights, and Melee cards are used to inflict damage. A special "Stage Card" provides the Stage Limit, which was a means to define when a character gets KOed, along with the strength of each attack.
Basically if a stage says "Stage limit is 15", and a character has taken 150% damage and has a weight of 5, you would just divide 150% by 10 (It's 15) and subtract the weight (Now it's 10), then compare those numbers (10 < 15). Attacks had strengths though, and those counteract character weights (10 + Strength). So if an attack with a strength of 6 sent a character's damage to 154%, and that character's weight was 5, it would look like this....
Damage = 154%
154% = 15 (heck no there ain't any decimals or rounding up)
Weight = 5
15 - 5 = 10
Strength = 6
10 + 6 = 16
16 > 15 (Since the attack result went over the stage limit, a KO was declared)
It looks complicated on paper, but it's actually pretty darn easy if basic math doesn't scare you.
Finally, scoring a KO doesn't instantly mean end of the game. In my game, the minimum Melee deck size is FIVE. When a character gets KOed, a "Stock" is lost. The players can decide for themselves the amount of stocks, and whoever loses all of their stocks loses. At the end of any turn if a player runs out of cards in their Melee Deck, that player is considered to have performed a "Self-Destruct" and loses a stock. (You can run out of Support Cards though without losing)
I haven't worked on the game in a long time.