I actually have a similar experience with a game/community.
The game was Battlefield Vietnam. And what a game and community it had in high levels of play.
It went through 3 very strong competitive CAL seasons and a 4th pretty good one. For about 2 years I'd say after it's release the TWL ladders/leagues were hopping and the very pro CAL teams were hoppin. I started a team first season of CAL with a few friends and we tried to find good players to join in the first season. I think we only finished like 8th or something bad. I got really fkn good at the game, in infantry. My core teammates got really fkn good too. We had the best chopper pilot in the game with us. Our plane pilot was one of the best. I was considered by some one of the best infantry in the game, one of my competitors turned out to be hacking : (. 2nd CAL league we got to the semi's as we got more serious. I think the 3rd season we placed second and the 4th one we got 1st. We held the TWL infantry 5v5 ladder at the #1 spot for a long time. We battled up and down 1st-3rd in the TWL 8v8 ladder, but CAL was our main concern. There was some serious competition. During the CAL season we'd scrim like 7 times a week before the match, and have a pre game scrim every week on the day of the match. We'd have practices on Sunday, work on strats all week on the forums, always be on practicing the map with each other. By the end of our run we had formed a solid 10man team that was just amazing to be a part of. We were all friends, always on vent, practicing, pugging, etc... and there was always room for improvement. For games, you could roll out with a simple beginning strat and wing it, or get really in depth with all the variables that could happen on that map.
The best part about the BF:V community was that it wasn't too too big. You really knew most of the players from all the teams. We were all friends outside of matches. All the time, on a lot of nights, we'd have pick up games where we'd all get on vent, have 2 team captains, pick teams, and go at it. Man, what a blast that was. We'd do this for hours, talking shit to each other in vent, having a great time. We could always find a scrim, be it 10v10 to work on strats, or my favorite 5v5 infantry only scrim to hone our skills on the city maps. I had maxed out my xfire friends list within 2 weeks of joining CAL, I couldn't add anymore friends.
What made the game such a great game, like demigod, and I'm sure GC2, is that there was a huge focus on individual skill as well as teamwork. You had to have both to succeed, it was really about both. Unfortunately, like GC2, in the end it just died. It's amazing to me how dead it is now actually, it's quite depressing. Nothing yet has taken it's place. It's now near impossible to find a server with enough people for a good infantry game. The Hastings air map server is still pretty hopping, but usually only 20-30 out of 40 slots full, which is fine.
Man, I have such good memories of my teammates, the matches we played in, the games we went in as the underdog and came out on top, going way above and beyond everyones expectations. I remember the painful losses where one of our guys would make an unbelievable mistake and lose the game for us. The CAL matches were so intense at moments, trying to get vent quiet was near impossible sometimes.
I haven't seen a community quite like this one since the game died out. I had a go at competitive Battlefield 2, and it just wasn't the same. Like GC2, there were leagues in the US, EU, all over the world. There was even a world tournament that was very successful (but in my mind unsuccessful due to high pings in matches). One of the big reasons to be honest, is World of Warcraft. Throughout the end of BF:V, WoW slowly took away half our roster. I think that game is pulling too many skilled players away from other, more pvp oriented games out there. It's sad really.
Unfortunately, Demigod has nowhere near the community that Battlefield Vietnam had in it's prime. The community right now, and when you could consider it at it's prime, is quite small. Very small, actually. There are no competitive leagues, no ladders, no in game support for any of this either. I think the game might be a bit more popular atm if it had been released with team support and a ladder, maybe with some tournaments along the way.
Vietnam did have some problems with hackers, although not to the extent GC2 did. The worst case of it was a guy from one of the top teams, although not the top one, finally got caught for map hacking in matches and out of them (people finally caught on, he was a little TOO good) by the 2nd or 3rd CAL season. IMO, that was way too late. He had already flipped games that they should've lost but won. It was pretty easy to tell who was hacking to be quite honest, and all the guys we were skeptical of actually were and got caught/banned/e-smacked.
I know how you feel about the demise of GC2, your game, and your community. It'll never come back is the worst part about it 
. TBH I would've like to see something of this sort with Demigod, but the game has already been de-populated to the point of no return.
