Here is the full list of all 47 Titan Attacks achievements.
Perfect Challenge Level 63
Used 25 smartbombs
Captured 100 live aliens
Perfect Challenge Level 98
Perfect Challenge Level 91
Destroyed 100 saucers
Perfect Challenge Level 84
Perfect Challenge Level 77
Perfect Challenge Level 70
Perfect Challenge Level 7
Captured 50 live aliens
Destroyed 50 saucers
Perfect Challenge Level 14
100 aliens escape capture
50 aliens escape capture
25 aliens escape capture
Completed the Titan levels
Everything maxed out
Maxed gun power
Guns and addons maxed
Killed 100 parachuting aliens
10 aliens escape capture
Maxed gun bullets
Completed the Saturn levels
Captured 25 live aliens
Added all addons to ship
Upgraded addons to maximum rate
Killed 50 parachuting aliens
Completed the Mars levels
Perfect Challenge Level 56
Captured 10 live aliens
Got 100 skill shots
Killed 25 parachuting aliens
Perfect Challenge Level 49
Perfect Challenge Level 42
Completed the Moon levels
Perfect Challenge Level 28
Perfect Challenge Level 35
Got 50 skill shots
Destroyed 25 saucers
Perfect Challenge Level 21
Got the x9 multiplier
Killed 10 parachuting aliens
Completed the Earth Levels
Got 25 skill shots
Got 10 skill shots
Destroyed 10 saucers