Here is the full list of all 38 Captain ToonHead vs the Punks from Outer Space achievements.
Destroy 100 Aero-C.A.A.T. Units.
Buy every Brent-X Blaster's upgrade in the Weapon's Lab Tech-Tree
Complete all levels within Stage 1: TrashTown
Destroy 160 P.U.N.K. Units.
Buy your first upgrade in the weapon's Lab Tech-Tree
Complete level 1-1.
Install your first toonret in a level.
Complete all levels within Stage 2: EnerMines
Complete all levels within Stage 3: TechnoLabs
Complete all levels within Stage 4 : P.U.N.K. HQ
Uninstall your first toonret
Use eagleview 100 times.
Install one of each toonret type in the same level.
Use a ToonRide! for the first time.
Destroy 200 Cyber-C.H.I.C.K.E.N. Units.
Destroy 10 T-R.A.D. Units.
Destroy 100 P.U.N.K. tech devices with La Chancla
Add up to 2000 damage with Brent-X Blasters
Collect 10000 scraps from enemies
Buy every Chancla's upgrade in the Weapon's Lab Tech-Tree
Buy every TurboMjölnir's upgrade in the Weapon's Lab Tech-Tree
Buy every Pizza Rocket's upgrade in the Weapon's Lab Tech-Tree
Buy every Lady Jubilee's upgrade in the Weapon's Lab Tech-Tree
Buy every Sir Frost-eee's upgrade in the Weapon's Lab Tech-Tree
Buy every Señor Pigñatas' upgrade in the Weapon's Lab Tech-Tree
Buy every Queen Dio's upgrade in the Weapon's Lab Tech-Tree
Upgrade any Toonret into lvl-5 during a battle.
Destroy 400 Cyber-C.H.I.C.K.E.N. Units.
Destroy 300 P.U.N.K. Units.
Destroy 200 Aero-C.A.A.T. Units.
Destroy 20 Terra-S.H.A.R.K. Units.
Destroy 30 T-R.A.D. Units.
Destroy 500 P.U.N.K. tech devices with La Chancla
Add up to 10000 damage with Brent-X Blasters
Collect 50000 scraps from enemies
Buy all upgrades in the weapon's Lab Tech-Tree.
Collect every trophy
Destroy 50 Terra-S.H.A.R.K. Units.