Here is the full list of all 17 Madballs in Babo:Invasion achievements.
Win 5 games of Team Skirmish
Find all 50 secrets in the campaign
25 kills using the Striker energy mode
Crush 100 enemies using Magmor's Colossus ability
Play with somebody who has the Playbrains rules achievement
Unlock your first item
Host a 4-Player co-op game
Finish the campaign
A fierce kill using every weapon
Win a 6+ player CTF game with the most points on your team
Win an 8+ player Invasion game
Unlock the Officer Ranks
Unlock the Hero Ranks
Achieve the top Hero Rank
Play as every B*D*I class in a versus match
Play as every Scorched class in a versus match
Get over 2500 points in a skirmish match