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