Your mention of the skateboard and my memory of the parfait once appearing in place of the watermelon I usually get on 6-3 had me hoping it was to just collect 5 of the same type of fruit in a row while on the skateboard but I played around with it and only ever got the watermelon. Actually managed to get 6 of the same in a row on the skateboard but only got the watermelon after the 5th. Hopefully someone knows, I think you're right about the skateboard though.