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