Here is the full list of all 13 Zero-G achievements.
Score a goal
Score 250 goals
Win a match
Win a match 8-0
Win a match in less than 40 seconds
Win a tournament
Win a campaign
Win a hard camaign
Win a campaign without upgrading your team
Hire a Star Player
Tackle 10 opponents by hitting them with a charged shot
Collect 50 Power ups
Activate the Pretty Pretty Indie pixels secret