I recently attended BrickCon 2015 in Seattle and saw this outstanding mosaic. It's roughly 5 feet tall and 7 feet wide. However, I have no idea what the mosaic is. It looks cartoonish, but I don't recognize it. Please identify what this mosaic is based on.
It's Dr. Wily's Castle from Mega Man.
If you want, here are some other images of it (linking to pages, so you get detail, rather than just posting images):
and Ty Keltner, the builders video interview:
thanks for coming to BrickCon.
This piece is by Ty Keltner, a Lego builder from Juneau, Alaska. You're right about the subject matter. That's Wily Castle from the 1988 video game Mega Man 2. You're pretty close on the dimensions too, it is exactly 60 inches by 80 inches. Ty built it in his garage over the course of a year.
You can find more of his stuff here, though it doesn't look like it has been updated in a while: http://www.mocpages.com/home.php/34777