This game took around 3 hours 30 minutes to beat again recently. Beat it in the 90's. I had to redo stages 1-3 since I had the jump button set to turbo and it was fucking up my jumps and making it way harder. So I wasted alot of time on that. Check out the version without commentary too.
The only level where I sped things up with save and load states was the final level where I made a save at each checkpoint, to avoid being sent back to the level beginning. I did this because I already beat this level on the hardest setting in the game, and I was just capturing this to make a playthrough video.