The spirit should be more like 'This repo is a fork of'; The language you chose suggests that his project was derived from yours. Also, I think you need to do slightly different things to comply with the license. It says:
"You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use."
Kind of disappointing. This was the first game I've ever written so it kinda means something to me. From what I've read, it seems that you had no intention of mentioning that you copied it from me (Nope you didn't fork it :p). But I guess I'm flattered to know that it was good enough for you to "re-share".
Mark Steve's version is open source so it is okay to blatantly steal from it. However, the author needs to fulfill the criteria set by the license that Mark Steve chose.
That's exactly what my comment said. (Although fulfilling the license doesn't mean he actually has to fork.)
In my opinion, he still isn't technically in compliance though since the license text says "You must...provide a link to the license, and indicate if changes were made." I could see this being issue if, for example, Mark Steve removed his code from github, then it wouldn't be clear what license the code was under.
This repo forked by : Don't Touch My Birdie http://marksteve.com/dtmb