Okay, so having finally officially unlocked all the characters in TvC I feel am ready to give the game a fair micro review.
To start off, the game feels similar enough to its predecessors to be comfortable to fans of the series. However, it gets major points for being a simple fighter (in the scope of fighting games) and thus appealing to people who might not otherwise give it a second look. I think people in general would enjoy the game if they gave it a shot. That being said... NO ONE knows who or what Tatsunoko is (not even my spell checker...). That is a major problem with the game gaining popularity in a casual market.
Moving on past the general appeal of the game we get into the actual control scheme. Quite literally it is 4 buttons and a control pad/stick. Easy. No swapping of control modes. No major flaws. Not even elaborate controller inputs (THANK GOD). The most you are asked to do it like a half-circle and two buttons at the same time. This is a godsend for those of us who dread seeing two full circles and a six button sequential combination when we pull up our favorite character's move list for the first time. I personally use a gamecube controller (the D-pad seems faster to me so I am working on a thumb callous). I have tried the standard Wii controls... they don't feel good to me but a classic controller fixes the problem. I imagine an actual fight stick is probably the best (as always with these games) BUT the $70+ price tag is a bit of a deterrent for a cheap gamer like myself.
The art style is perfect for this type of game... the only thing that bothers me about it is I wish I could see more of Tatsunoko's animation not just still frames...
The music is quite good but nothing that jumps out to me. Some songs really strike me, others seem to just fade away... and none of them seem original to the game (save perhaps the opening cutscene? which isn't remarkable).
As far as game balancing and design goes I think the game is quite elegant. It doesn't get convoluted but it has enough complexity to make me feel like there is always something new for me to learn. For example, you can do a super move. Cool. But you can also do a double supermove with your partner. Awesome! But it doesn't end there, you can do a supermove followed by a supermove to switch your characters. The game also has a thing called a Baroque combo, which while silly sounding makes for some very very fun and overwhelming results in a fight. When done right it can make a supercombo look like childsplay.
The characters themselves are also fairly well balanced and not many stand out as too incredible/unstoppable or just plain terrible. I can see all of them having their own unique uses. The only thing is the game seems totally directed to all out assaulting making turtle characters hard to play the way they were meant to. When the pace gets set for all rush-down style play blocking takes a back seat to whooping ass (which again lends itself to a casual player very well).
The online play is great only held back by the Wii's inexplicable ability to suck at using the internet.
Finally, the game's sense of humor is the icing on the cake. The fact that there is a mini shooter game that you unlock by beating the credits minigame (yes... there is a minigame in the credits). Makes me smile like not many other unlockables have in a long long time. (mostly unlockables make me groan to be honest). And even though it is a trivial thing... I love dealing damage in billions.
Overall, I approve of the game. It doesn't break too much new ground but makes the genre of fighters seem a lot more interesting as a whole. It is great as a way to break the massive learning curve barrier into the genre if you are willing to go out of your way for it. It doesn't seem like it will be a superstar in the marketplace but it has a place in my library as one of the games I am proud to own.