If you wanna beat the jaguar race a diffent way, heres how:
At the start of the race, use your hand closest to the space bar to charge, then before you get to the first narrow path switch hands (so they're crossed over each other) and use the former charge hand to direct. When one hand gets tired switch so they cross/uncross and continue this way.
I got through that way; easy as it could get. Be careful though, when the jaguars gain on you it's nearly impossible to get ahead again.
At the chapter before the croc hunting zone (may work else where in rivers), try trusting speed to save you; go as fast as you can. This method managed to save me and it looks fun to!
To jump through walls, you must have a cliff, ledge or something else high up that you can climb up to. When you are on top of the cliff/ledge etc, charge jump to the Kuzco door or any other closed door to fly through the wall. If you are too close to the edge of the cliff/ledge etc, you might fall of a cliff (if there are any) and lose a life. Sometimes, you might just his the wall and fll back to the ground or onto the door's frame. If you are placed in the right position, you will fly through the wall. This cheat works best for the Mountain -- Chapter 2 Bird door at the end.