The one in blue is Popo, and the one in pink is Nana. They use their incredible jumping powers and hammers to break blocks and climb to the summit. They grab veggies, and if they can catch the condor at the end, they conquer the mountain. Other than breaking blocks, their hammers are good for sending foes flying, climbing down from blocks, and destroying icicles.
The Ice Climbers' Final Smash. This giant ice mountain appears in the middle of a stage--it's incredibly slippery, so it's hard to control yourself when traversing it. In addition to being slick, this ice is also COLD, so opponents will take damage just from touching it. Attack the ice, and it will take damage and slowly shrink. Is it actually useful? That's a mystery.
The Ice Climbers' goal is to climb peaks. Just below each peak is a bonus stage where these bonus items appear in this order: eggplant, carrot, cabbage, cucumber, corn, turnip, pumpkin, Chinese cabbage, potato, and mushroom. You'll also get points for grabbing the condor at the peak after collecting the veggies. Why vegetables? That's a mystery for the ages.