Mentioned this briefly on TIGSource forums but...
1 - This game was listed on FGL (not 100% certain)
2 - The game is hosted by AGAME.COM and carries AGAME branding (http://www.agame.com/game/Green-Gray-World.html
3 - You are not credited in AGAME version of the game
Conclusion: he made more money than he told you
The reason I know this is because I was looking at your games over at GameJolt and came across this one. I was looking for a game to port to flash. Next thing I remember is seeing this same game on FGL but I was kinda confused. I didn't know if it's you or not of if I somehow confused his game with yours.