I only collected the apples/hearts with Twilight Sparkle and just sort of rushed through the levels with the other five ponies.

Twilight Sparkle: 00:00
Rainbow Dash: 10:00
Applejack: 19:28
Pinkie Pie: 29:28
Rarity: 35:41
Fluttershy: 41:33

Link to game:

http://www.mylittleponygames.biz/game/adventure_ponies.html