To do this you'll first have to download the old version of this game which Denny perfectly explained in another thread.

Postat inițial de Denny:

Still works by downloading the old version:

1. Open Steam console by pasting this into any web browser url bar and pressing enter

steam://nav/console

2. Paste this into console and press enter

download_depot 673660 673661 635070894459089531

3. Go to game folder (right click on game -> properties -> Local files -> Browse local files) and delete all files
3. Go to "[Steam installation folder]\steamapps\content\app_673660\depot_673661" (in my case "C:\Program Files (x86)\Steam\steamapps\content\app_673660\depot_673661") and copy everything to game folder
4. Run the game and enjoy

Now when you're done with that you're ready for the following steps:

I've noticed that the buzzsaws move in different speeds depending on what graphic quality you have selected. For me the lowest graphic quality setting makes the buzzsaws go hyper speed and will be impossible to dodge, and even the highest graphic setting is too fast to dodge, even with perfect timing! (they go way faster than the buzzsaws that I've seen in the video guide.)

If you have this problem too all you need to do is to launch the game in windowed mode and minimize and maximize the game a couple of times. This will cause the buzzsaws to glitch out and most of the time leave the play area and will leave you a hazard free path to the goal. If not all buzzsaws have left the play area after minimizing and maximizng the game just reapeat until they're gone. This works on every level, but this exploit won't work on the laser and laser shots.

If you have problems with the last level and only the only reason you play this game is for the achievement, I'm happy to inform you that you don't need to finish the last level since the last achievements unlocks by just opening the last level.

I hope this guide was useful. Good luck!