If you want to speedrun the game but not lose all your progress with the time-consuming collectibles, here's a guide on how to make a copy of your save file:

This is the file directory where the save should be located:

C:\Users(yourname)\AppData\LocalLow\Atari

You can just copy the whole Atari folder (assuming you don't have any other Atari games) and paste it to your desktop. Then you can go into the game and start from a fresh save file for speedrunning purposes.

When you want to continue your progress with the collectibles, just copy the backup save file from your desktop and paste it back into the original file directory. When you open the game, you'll be able to continue where you left off! (Don't forget to repeat these steps when you go back to speedrunning!)

Happy Speedrunnning!