Wow. Thats all i have to say. If this game lives up to what the forums say, and is developed by the community of all people, then this will be one amazing game. Its called Theme Park Builder 3D.
This game will be a 3D theme park business type game, wehre you can develop roller coasters with no limitations and you can build, yeah BUILD flat rides. The website is all about ideas going into the project and it looks like it will be a great game. No lagging? Thats going to be a good obstacle to come by! The game is a mix of RCT and NoLimits. I think this is the game where you will be able to create exact recreations of parks like sfgam. I'm going to help contribute to this forum, and I'll tell ya, this game will be GREAT!
SITE: http://www.tpb3d.net/