Happiness is Peak 1's back country. Happiness appears in both SSX 3and SSX Blur.
You can find the Jump Big Challenge near the top of Happiness. This one is fairly straightforward: you will have to jump through a series of metal hoops that are somewhat suspended in mid-air. If you are having trouble jumping through the hoops, try riding up onto a hill before jumping. If you jump and sway too much to the side, jump in the opposite direction to hit the dead center of the hoop.
You can locate Dizzy Spells by going left of the Jump Big Challenge. This is a fairly easy Big Challenge, as you will have to perform the following spins: 180, 360, 540, 720, 900. For the last two spins, you will likely have to fly off of the taller cliffs, and perform the move on the way down.
Located near session 6 of Happiness, Danger consists of you boarding through the upcoming tunnel without getting hit by the ice sickles that fall from the ceiling of the cave. To do this, you must simply stay alert, and watch up ahead for what is going on.
This is considered the hardest challenge on the Happiness side of things. Your objective is to make it down the mountain with less than 8 seconds of being in the air; thus, you must avoid all cliffs, or go so slow that you board down them instead of jump. In order to fully defeat this Big Challenge, you will have to drift to the right side of the mountain. Practice makes perfect.
From the top of the mountain (Happiness), go right at the fork in the road, and left make a sharp left turn, looking for the tower of light. This mission consists of you finding several areas. Go straight to collect the first one, and right, into the tunnel, to collect the second. Go straight after this to collect the third, and you will find the next two arrows in two caves after long waits, but you can't miss them, so don't worry. Afterwards, hug far right to drop down and collect the last arrow to complete the mission.