BABBDI

There is a video which shows speedrun tricks: https://youtu.be/WIr9paJUsrk. If you just want the achievement and the end trick which requires flying outside the game boundaries is too difficult you can (after obtaining propeller shown in video) instead fly to the talking head and follow normal walkthrough from there with the aid of propeller. I was able to finish the game under 3 min.

Credit for the video goes for https://www.youtube.com/@apterous420/videos who has made also videos for other achievements in the game.