Here is the full list of all 20 Xbird achievements.
Time in game 130 minutes
Time in game 120 minutes
Time in game 90 minutes
Time in game 60 minutes
40 KILLS
35 KILLS
30 KILLS
25 KILLS
Time in game 30 minutes
20 KILLS
Time in game 20 minutes
15 KILLS
10 KILLS
Time in game 10 minutes
5 KILLS
Time in game 5 minutes
3 KILLS
1 KILL
Time in game 1 minute
Time in game 10 seconds