Here is the full list of all 14 Darts Up achievements.
Throw on the Triple 6
Get Three Doubles in the same round.
Throw the dart on the Double
Throw Three times on the Triple.
Throw Three Times on the Bulls Eye.
Throw on the Triple 20 + Triple 1 + Triple 5
Get 45 Points in the same round.
Complete the Level 5 in Arcade Mode
Complete the Level 4 in Arcade Mode
Complete the Level 3 in Arcade Mode
Complete the Level 2 in Arcade Mode
Throw the dart on the Triple
Complete the Level 1 in Arcade Mode
Throw the dart on the Center