Here is the full list of all 50 Velocity 2X achievements.
Get 100,000 points in the credits minigame
Complete level 50
Shoot 10,000 pieces of glass
Unlock all abilities
Teledash through two Vokh at the same time
Destroy 50 Vokh Guards
Collect 10,000 crystals
Destroy 2500 airborne enemies
Shoot 5,000 pieces of glass
Complete a level without letting go of boost
Collect 5,000 crystals
Rescue 6,000 Jintinda
Get stuck in a door
Disable three switches within 1 second
Unlock a bonus level
Hit every speed pad in Level 25
Kill every type of enemy (doesn't incude boss battles)
Gain above average XP in half the levels
Defeat a Vokh
Survive the first encounter with General Glaive
Gain your first PERFECT medal
Fly over your first speed pad
Use double the firepower!
Disable two switches within 0.5 seconds of each other
Partake in your first Daily Sprint Challenge
Dock your ship for the first time
Get squished at the bottom of the screen
Look in every folder in Flight Computer
Collect all data packs
Gain 25 PERFECT medals
Earn Gold medals on all Critical Urgency levels
Boost all the way through level 3
Unlock all bonus levels (25)
Gain 50 PERFECT medals
Get a PERFECT medal on all Critical Urgency levels
Complete all bonus levels
Perfect all speed levels
Complete all speed levels
Trigger a speed pad 4 times in under a second in level CU05
Avoid every speed pad in level CU02
Boost and sprint all the way through level CU02
Destroy 6 turrets in level CU04 in under one second
Perfect all Dual Core Levels
Complete all Dual Core Levels
Perfect all Speed Runs
Race through Level DC02 without letting go of boost!
Die by leaving one ship behind
Destroy 16 turrets in 2 seconds in Level DC08
Play 60 different Daily Sprints
Obtain max crystals in 20 different Daily Sprints