Here is the full list of all 20 NEON Ultra achievements.
Played 100 full games of NEON Ultra
Played 50 full games of NEON Ultra
Kill 15 enemies without moving
Achieve a 600x Combo
Amass a score of 10,000,000 in one game
Kill 800 enemies in one game
Achieve a 300x Combo
Amass a score of 5,000,000 in one game
Kill 500 enemies in one game
Reach maximum weapon power
Amass a score of 1,000,000 in one game
Amass a score of 777,777 in one game
Amass a score of 500,000 in one game
Kill 100 enemies without taking damage
NEW_ACHIEVEMENT_DESC_1_2
Die for the first time
Kill 100 enemies in one game
Achieve a 10x Combo
Keep a shield active for 60 seconds
Survive for 120 seconds without shooting once