Here is the full list of all 46 Antisphere achievements.
Reach level 5
Unlock 8 specials
Reach level 10
Reach rank 10
Score a point on a stunned opponent in an online match
Finish a time attack challenge without touching a wall
Win your first online game
Play 15 online games
Challenge a friend to an online match
Reach level 30
Reach rank 5
Play 50 online games
Get gold time in 10 challenges
Get gold time in 23 challenges
Reach level 15
Reach level 20
Reach level 25
Pass through a portal 100 times
Finish a local multiplayer match
Fire 999 projectiles
Finish challenge 2 without dashing
Win within the first minute of an online match
Score a point with a direct hit using curve shot
Win a game without getting hit
Win 5 games without getting hit
Win 10 games without getting hit
Play a game on 8 different arenas
Reach rank 1
Reach Ace rank
Reach number 100 or better in ace
Reach number 50 or better in ace
Reach number 8 or better in ace
Reach number 1 in ace
Unlock 4 trails
Unlock 5 decals
Unlock 5 bodies
Unlock 5 shields
Unlock 1 of each cosmetic type
Play 5 online games
Play 100 online games
Win 5 online games
Win 15 online games
Win 50 online games
Win an online game without passing through a portal on a portal based arena
Score a point with a projectile that bounced 4 times
Win an online game without using a single special