Here is the full list of all 30 MechaNika achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
You made Manson the cat happy with Dennis' socks.
You completed the MechaNika project.
You didn't spend any money to complete MechaNika.
You completed MechaNika without a clue.
You discovered Nika's secret lab.
You got the saw disk.
You got the ignition system.
You won the RoboPodcast quiz!
You got your Project Silcharde poster signed by Mango Protocol!
You won the Ninja Turtles' quiz!
You got the flammable liquid.
You disguised yourself as grandma Rosemary.
You got the air compressor.
You got the projectiles.
You discovered the end of grandpas' story.
You discovered your grandpa's magazines in the hidden safe box.
You got the multimedia recorder.
You got the propellant.
You got the multimedia player.
You got a portable TV thanks to your trolling proficiency.
You fixed the Gate of Great Sacrifice!
You got the shrapnel.
You got the transmission chain.
You got the microwave emitter.
You couldn't stand Dennis' smelly socks.
You got the reflective panels.
You tried to leave school.
You flushed the dirty toilet in the school.
You interrupted a poor girl while she was in the toilet.
You exchanged your meal for some spray cans.