I think this is the hardest game that I have completed 100%, and I didn't use the save trick for the complete 32 levels with no super, although the 9 minute survival might be the hardest achievement anyway.
The other 2 games noted for their difficulty I have completed are Hexic and Dead or Alive 4. Hexic's achievement difficulty is wildly overrated. I finished them all in one night, a game that gives you infinite time to think about your next move isn't that hard imo, while for Astropop I had to practice every day for over a month to get the skill necessary to get the achievements. Dead or Alive 4's takes a long time but for an avid fighting game player aren't that bad.