No Man's Sky. Game was a disaster when it came out. For most games, a bad launch would have ended the game. But with NMS, the devs kept at it and constantly added new content over many years. I believe it's still actively developed.

That's what got me to play it. I only played it maybe half a year ago. I wouldn't have bothered if not for the fact that people were mentioning how much the game had improved. I wrote the game off after the bad press when it launched, but fortunately I was wrong and they did make something good out of it.