Ok, first things first, Mario Kart Double Dash is a VERY fun game, its just awesome.
So far im loving it, only complaints are that the Australian version says Miles per hour instead of Kilometres per hour (what kind of country still goes by miles, honestly?), and that the computer opponents always come in the same positions in every race of a GP, and you basically have to come first in every race to get gold. Thats all.
The tracks are brilliant, i have not found ONE track i dislike (although the desert one is more annoying than the rest), and their are shortcuts littered around the tracks, but they are harder to find and harder to pull off successfully than in previous Mario Kart games. I love the Yoshi track, Baby Park, the Donkey Kong track, and another track i unlocked the best. But i like every single track ALOT. Some battle tracks are... a little disappointing, but the one i just unlocked is absolutely awesome, and the standard ones are still fun, just one lame one in my opinion.
The music is decent, and tolerable, i LOVE the whistling tune in Mario circuit and Luigi circuit and others, its insanely addictive, im gonna be whistling that tune everywhere i go for the next few weeks i can tell. Some tracks you cant hear the music very loudly though.. for some reason, although that may just be me. Some songs are completely forgetable, and sound like they were just thrown together by a two year old in a few minutes, but the good outweighs the bad in the case, for me anyway.
The two people in a kart is where Double Dash's main new gameplay aspect comes into play. At the character select screen you choose two characters, and one kart. One character is at the back, the other at the front. You can make them switch places just by pressing the Z button. As far as i can tell, it doesnt make any difference to the handling of the kart when you switch characters around the kart during the game. Some characters are too big, or cant drive certain karts, for example Donkey Kong wont be able to ride in Baby Mario's pram.
There are lots of new items, as you all would know, each character has their own 'special' item that only they can use, and overall they all seem fairly balanced, noone's weapon greatly overpowers anyone else's special weapon. I'll let you find out what each characters weapons are for yourself. When you pick up an item it is automatically sent to the character thats at the back of the kart, so if you get a special, the character at the back of the kart gets it (ie if mario is at the back, the special will be a fireball). All the classic items return, except... for one,
ghost, and there are plenty of new items.
I got a chance to play Co-op play, its very fun. Basically its two players controlling one kart, one player drives while the other player attacks, you can switch at any time by both of you pressing the Z button at the same time. Co-op mode allows you to punch and kick enemies when you are controlling the character at the back, and you can do F-Zero like side attacks against your opponents.
The controls were a bit hard for me to adjust to at first, but after about 10 minutes i was loving it, and driving along with no problems. The controls really grow on you, every time i play this game it feels better and better.
The graphics are very Mario Sunshine-ish (there are lots of Mario Sunshine references throughout the game too), lots of colour and nice animated touched bring the game to life, and the heat effect seen in SMS and Wind Waker is there, although you dont notice it as much. The game runs very smoothly, even in 4 player split screen. Overall the game looks very impressive, the graphics are top notch.
Those are my impressions after about 6 hours of play, i LOVE Mario Kart: Double Dash!!