Here is the full list of all 19 Romans From Mars 360 achievements.
Complete Battle 5
Complete Battle 15
Complete Battle 50
Complete Battle 150
Arrow Speed Tier 2
Rate of Fire Tier 2
Blast Radius Tier 2
Critical Hit Tier 2
Ballista Tier 1
Ballista Tier 2
Ballista Tier 3
Kill Streak 20
Kill Streak 40
Kill Streak 80
Kill 10 Enemies in 1 shot
Total 1000 Kills
Total 10000 Kills
Total 100000 Kills
Pickups Full