This was posted on Facebook this morning, I assume it's from Vern:

"Anyone reading:
Sorry, I've been unable to support the game for years.  If you're reading this, here is a code for MM HD that will work if entered within the next month:
Registered To:
Free Code
Registration Code:
MM1-YPMDHTWWFUPKUJRBE
The online registration system ahs been very broken for a long time (old PHP scripts) so it's quite a challenge to process new codes or update old ones, but from time to time I could post a free code here if anyone is interest.
Please spread the word, and feel free to share this with anyone!"

I hope anyone that's been trying to get a code sees this.