Congrats, AWESOME name IMO..... Hmmm lets see.......
If FreeOnlineGames.com is worth about mid to high $xx,xxx - I would value this domain at high $xxxx, maybe even low $xx,xxx
Its a very nice name, although I think that as a few people have said low - mid $x,xxx value is nearer the money (but would still be tough to find a buyer).
Maybe to the right end user you might get more, but the online game/arcade market was saturated a long time ago and I think in the current market you would stuggle to get a buyer at some of the amounts people are quoting.