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 any level.
Defeat Hunter without taking any damage.
Defeat Pirate without taking any damage.
Defeat Shaman without taking any damage.
Collect 3000 ducats.
In a speedboat level achieve time better than 03:00.
Collect 1000 ducats.
Collect 500 ducats.
Collect all ducats, stars and crystals on every level.