Here is the full list of all 28 PIXELMAN achievements.
Rescue 2000 Citizens
Complete Arcade Mode on Hard Difficulty
Complete Arcade Mode on Medium Difficulty
Survive a fly through the asteroid field without taking any damage
You've rescued 40 citizens in a row in one gameplay
Eat 200 fried chickens in total
You've destroyed 3 buildings in a row!
Unlock all podiums
Hit by lasers for more than 20 seconds in total
You've destroyed a building!
Hit by rockets 10 times in one gameplay
Go between 200 rockets
Take down 10 enemy planes using Powerups
Rescue 100 girls in total using Pixelgirl
Pass through 100 trees
Cross 10 entire tunnels in the dark in total
You've reached 2000 points without being hit by anything in one gameplay
Cross an entire tunnel in the dark
You've heard the PIXELMAN theme 4 times in one gameplay
Survive for 5 minutes in one gameplay
You've made more than 9000 points in one game
Complete Arcade Mode on Easy Difficulty
Go between 50 rockets
Unlock Endless Spacestation Mode
Unlock Endless City Mode
Hit by two bombs from the same plane... and survive!
Unlock your first podium
I'm starting to think you're doing this on purpose