Here is the full list of all 12 Alien Attack: Pocket Edition achievements.
Kill 2500 aliens!
Kill the fourth boss!
Kill the third boss!
Kill 500 aliens!
Achieve 500 score points!
Kill the second boss!
Achieve 100 score points!
Die one time!
Kill one alien!
Die 50 times.
Kill 5000 aliens!
Kill the final boss!