NORMAL: Basically, you have to boost all the way up to the Wild Boar and kill him. But of course its not that simple - you have to get past all his minions first. By boosting up to them you lose shield power, but for each one you kill you get a little bit back. Spin attacks are the order of the day here, as you can often take 2 or 3 out at a time with them. This is especially true when you boost up right behind them. Just work you way through and kill them of. When you eventually get to the Wild Boar you'll find he is harder to kill, but a couple of spin attacks will get rid of him.
HARD: This is basically the same as above, only the minions are tougher and fight back.
VERY HARD: Again, much tougher than before. Don't bother with spin attacks because if you miss you'll lose to much speed. Boost up to the first pack and with your camera pulled back to its farthest, X attack all three in quick succession. You really need to take out a minion for every boost that you use hear. If your not killing at regular intervals then you need to restart. The Wild Boar slows right down at the end. The best attack is to go ahead of him, then wait for the check sign to get near and then spin attack him, just as he hits you.
Once again the strategy here is the same for all difficulties. From the word go your going to have to boost repeatedly, not letting up at all, collectin the capsules you come accross. The first door you'll have to move for is the fifth door. Move left or right to get through and get the capsule. Now very quickly get back into the horizontal position because there is another door dead ahead and is the same as the last one. Next is another vertical door. Pick up the capsule and get ready fo a set of double vertical doors. After is another verticle door followed by another capsule. Next is a pillar that is easy to dodge followed by a diagonal door. Then another diagonal door followed by a set of parallel pillars. Now get into the starting position and boost through the double vertical doors and a capsule. Next is a set of horizontal doors. then a capsule, and then a very, very tricky triple verticle doors. Then there is triple horizontal doors. After that get into the starting position. You'll see a boost pad. Hit that and the two straight ahead and then make damn sure you hit the oncoming ramp straight. Otherwise you'll have to restart.
NORMAL: This one could be easily completed on the first try if it wasn't for those damn unexpected dirt patches at the end. They slow you down and kill you. You see on this track from start to finish, your speed cannot drop below 700kph. For all the difficulties you need full acceleration. You don't need maximum speed here as it makes it you more likely to hit stuff. Ther is some traffic on the way, but as long as you stay central it won't bother much. Just make sure you don't use the boost until the dirt patches. Simple.
HARD: The same as before, except that you can't let your speed drop below 750kph. Again, full acceleration is needed.
VERY HARD: Probably the easiest of the VERY HARD levels. The only real problem is your speed can't drop below 800kph or your toast. The dirt patches are also a little bit more problematic and there is a little more traffic. Because of this you should put your speed meter at 50%. When you get to the dirt patches, timing is the key. You want to use your first boost just as you hit the first bit of dirt. That will take you through to half way on the second patch. Boost again. Now there are two optionS for you after that boost you can not boost again and hope that that boost will take you past the third dirt patch. Or to make sure that you make it you can boost again, but you have to beware or the shard left turning immediately after. Also on this difficulty, on the last corner you will be doing the loop as normal, but you will die if you do not boost.This is because of the angle of the loop make you lose to much speed. This only happens on VERY HARD unless you hit a wall as well on HARD.