Here is the full list of all 10 Kombine achievements.
Complete levels 41-50 in time trial mode in under 30 minutes.
Complete 50 levels.
Complete levels 31-40 in time trial mode in under 15 minutes.
Complete levels 21-30 in time trial mode in under 10 minutes.
Complete 40 levels.
Complete 30 levels.
Complete levels 11-20 in time trial mode in under 7 minutes.
Complete 20 levels.
Complete levels 1-10 in time trial mode in under 2 minutes.
Complete 10 levels.