Here is the full list of all 9 Kao the Kangaroo: Round 2 achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Collect all ducats, stars and crystals on every level.
Defeat Pirate without taking any damage.
Defeat Hunter without taking any damage.
Collect 3000 ducats.
Defeat Shaman without taking any damage.
In a speedboat level achieve time better than 03:00.
Collect all ducats, stars and crystals on any level.
Collect 1000 ducats.
Collect 500 ducats.