Look in your Blockland program files for the Blockland logo, an then crop it.
I meant something that was this size.

That is directly from my steam library. And I mean that size I mean something that fills up the entire rectangle. (And not be pixelated.)
EDIT: I think you thought I meant an icon for my desktop. But that wouldn't help me. You think it gives me another program that is exactly like blockland but has steam stuff put into it. What it really is makes it so whenever I open blockland, it detects it and notifies my friends I'm playing it. Sometimes, it incorporates the steam overlay thing so I can take screenshots and stuff.