[raincole]

Personally I know it's about edge detection at the first glance. But I think you should have two things:

1) Make it clear that the lack of instructions is intentional

2) Have a "pixel inspection" tool so we can check the exact RGB values in the expected and diff images more easily.

[szpro]

Thanks a lot, I think this is valid feedback and we will do that. About 1) we made assumption that for ranked challenges it would be obvious why it is vague, but we can fix it.

Thank you!