Here is the full list of all 9 Kao the Kangaroo: Round 2 achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Collect 500 ducats.
Collect 1000 ducats.
Collect 3000 ducats.
Defeat Shaman without taking any damage.
Defeat Pirate without taking any damage.
Defeat Hunter without taking any damage.
Collect all ducats, stars and crystals on any level.
Collect all ducats, stars and crystals on every level.
In a speedboat level achieve time better than 03:00.