Luckily, there is only one known way to fake speedruns: speedhack. Speedhack is a hack that slows the game down, making levels easier. To make run look like a legitmately done run, cheater speeds the footage up in the video editor. I need to note that screen with level name and description and "press any key..." popup ignore speedhack, making run harder to fake. Maybe, someone who will read the guide will probably fake one run or two, here are the ways of detecting a faked run:

- maybe, run without music and sounds can be faked, so be aware of that. With speedhack, music in game distorts, like sounds.
- if cheater forgots that screen with level name and description and "press any key..." popup ignore speedhack, and these have played faster in the run, reject this run IMMEDEATLY. NO EXCEPTIONS.
- splats around gooball after landing may not appear. It can be normal, when you jump exactly in the same frame with goo landing. Its hard to catch this timing, and in legitmately done runs it may not appear, or appear, but rarely. In speedhacked runs, it can appear much more times. That can be kinda sus.
- too awkward movements. If runner is a professional player, it could be normal. Spotting the differences 

between pro gamer movements and movements in a hacked run is almost impossible. - faster spinning gears. Really I dontt know if gear speed is always the same, or its being set by randomizer.

Here is an example of a hacked Platforms of Goo run:

If you suspect run to be illegitmate, ask runner for original footage of run. He should upload it to Google Drive or mega.nz or other website.