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 on the Triple 20 + Triple 1 + Triple 5
Throw Three Times on the Bulls Eye.
Complete the Level 5 in Arcade Mode
Complete the Level 4 in Arcade Mode
Throw Three times on the Triple.
Complete the Level 3 in Arcade Mode
Complete the Level 2 in Arcade Mode
Throw the dart on the Center
Complete the Level 1 in Arcade Mode
Throw the dart on the Triple
Get 45 Points in the same round.