Merlin Racing Strategy
From ChainsawYaK

"Go ahead and race!"

General Strategy

Lay mines or grenades right after boosting forward off of the blue arrows laid out on the tracks. A computer racer will still take the boost, and the grenade/mine will be unavoidable. If placed correctly, a computer will always crash into it and the arrows will be free of obstacles the next lap when you need the boost. 

"Grenades and mines blazing!"

Super Boost: As you begin the race, right after the 3rd light comes on, and right after the 3rd beep ends press the accelerate button. This will give your racer a boost in speed, as if he/she has just hit boost arrows or used the boost icon. This is extremely useful against bosses, and gives you an extra boost in normal races. Watch out though, in a normal race you are all the way back in the 7th place position so if you're not careful you will run into the back of the racers in front of you. 

"Super Boost power!"

Use aggressive karting. This may sound silly, but if you ram into the computer a couple times, it will severly disorient them. If you are slightly ahead of a racer, bump into them and smack them in the face with a grenade. If you are on the outside of a group of item boxes and a computer racer is next to you, bump them over so they can't get the power up. Ram them into corners of walls, other racers, signs, plants, etc. This will give you the edge you need to win the race. 

"Nobody said karting was fair!"

Take wide turns sharp. If a turn is really wide, the computer will take it as wide as possible. You do not have to do take turns that wide, taking them sharply will cut out a large gap between you and a computer racer, and can sometimes lead to victory.

"Steer with precision!"

If at all possible, do not use the remote as your controller. It's awful, the back of the box even says it's not recommended. If absolutely necessary, instead of tapping the direction you need, wave the remote at the player which will cause the signal to be repeatedly sent therefore allowing somewhat smooth gameplay. 

"Use your racing skills!"

Boss Strategy

Boss #1: At first the boss will seem impossible. He starts off by cheating, leaving slightly before the 4th light when you are allowed to go. It takes about 10-15 tries before you realize you cannot beat this boss the conventional way. You have to realize everything is a diversion, everything but the boost arrows. Ignore all item boxes, and take all turns sharply. You won't start to gain ground until the second lap in which you will have enough slack to be able to pick up an item box. Pelt him with a Missile (homing missile is preferred, as always) Once you are ahead of him, at about the 3rd lap, the rest is a piece of cake since his snow bombs are no longer in your way. Once he is beaten he will relinquish the elusive 1st Zystral Crystal. 

"Jump in a kart and Go, Go, Go!"

Boss #2: This boss cheats even more than the first boss did, she leaves at about the 3rd light, and your stuck for almost a second waiting for the 4th light. 1 Second is quite a long time, because this boss really moves. Ignore the 1st Item Box, it is way out of your way, and you will lose a lot of ground if you try to take it. Take the first boost arrow, but veer to the right because the boss will have dropped 1-2 rocks directly in front of it. Doing so will avoid the rocks and you will gain some ground by taking the turn sharply. The second item box will be a bit ahead on your left atop a small hill. On your first lap you can go for it, but you have to hope it is either a Homing Missile or a Boost. If you take it, keep your speed up and jump off of the hill. You should be fairly close to the boss, and once you are in front of him it is easy to stay ahead of him. The third lap around, lay as many mines/grenades as possible toward the middle of the track and he will most likely crash into you giving you an even bigger lead. Once beaten he will cough up the 2nd Zystral Crystal.

"Don't give up!"

Boss #3: This boss is pretty much like the other bosses, but this time you are racing on water. This is generally a good thing, you don't slow down as much when turning, and you accelerate slightly faster. Be sure to use your preliminary boost, this gives you quite an edge. The first item box is way out of your reach, but it's not a problem since the boss takes the turn so wide he will snag it before you could get to it. All of the item boxes placed on wide turns will be out of your way, but they will all be procured by the boss. All of the item boxes on the inside of turns are easy for you to get, and rarely touched by the boss. As always avoid the eggs he lays in the water. Wait until you can get a substantial lead, if you can only get a miniscule lead he will bump you out of the way.  Once beaten he will relinquish the 3rd Zystral Crystal.

"Watch out for the projectiles!"