The balloon augment once activated randomly puts you on another hexagon.
You need to buy it from a random shop, I bought it on a random shop in Tournament 5, once you buy it and install it, the best way to get the achievement is to stand next to a treasure (bags with a "?") and then press
to highlight the balloon and then press
to activate it, this will send you flying randomly, if you end up flaying over or landing on a hexagon with a treasure on it the achievement will pop.
This is the exact moment I got the achievement
Notice the Achievement description says "Use balloon augment and land
on a treasure" but you don't need to land on it, just flying over it will do.
I don't know why this is a very rare achievement with just 0.06% on XboxLive...