First off if ya didn't read the description. Cheat engine required.

If you don't have it, do a google search and download it. If you're not comfortable with that feel free to memorize a white route to a white door to get a white achievement. For everyone else instructions below.

1. Open up cheat engine once you are sitting inside the game. Load up the level and then ALT+TAB out to cheat engine and select the open process button(below File).
2. Select "The Unfinished Swan" and click Open.
3. By default you should be searching for a 4 byte, you can verify by looking to the right side of cheat engine beside "Value Type"
4. Now the easy part, throw 5 paint balls at the ground, wall, sky, whatever. Search for 5 using the "value" box. You'll get tons of results.
5. Throw 5 more, change your value to 10. Your results will shrink even more. Once you have your results to about sub 15 continue the level all the way up till you get across the wooden bridge by the kings statue. Tab back over to your cheat engine and look for the large consistent numbers and ctrl+click all of those values. Once they've all been selected hit the enter key.
6. Now that all your values have been identified, select them all at the bottom(shift click works here) and change them to anything under 3. (I went with 1 just in case)
7. Fall down the hole, enjoy your achievement. If you liked the game, go give them a positive review.