A racing game with no track, or reason to stay on the track?
That sounds boring. Just imagine the same idea with a fast running character.
It just seems pointless. Twisted metal or vigalante 8 is similar but with the objective of fighting eachother
I think rules, or objectives are necessary, even if they aren't clearly defined, but are merely emergent. I haven't tried minecraft, but I watched some vids, and even though there isn't leveling and such. You have the objective of creating a cozy place to survive the night, and other people made it about building impressive structures, or rollercoasters.
Maybe the racing game would be fun if a bunch of people got together and were able to create and follow the rules of a game of tag, or a trick or high jump contest. A racing game doesn't give you as much to do as minecraft, and isn't as complex a world. Keeping in mind I havet seen the game you're talking about. It'd be like if minecraft only let you walk around and not collect or fight or dig or break or build. Just walking, but faster.
I think open-ended games need to have interacting consequences for actions and for not taking action. The less rigid the goals, the more complex the world has to be. In gta its fun to drive around and kill random people when you're not doing missions because when you do, it becomes a game in itself. Cops chase, and that becomes a game of stealth or survival, sometimes racing away from a scene trying to keep your car in tact also becomes a game because there are cars everywhere. If you could just drive down the sidewalk forever killing everyone it'd get boring quickly, the same if you just drove in the city aimlessly.
That's one of the things spore suffered from now that I think about it. You're not free to do anything really other than the objectives. You spend time in the most impressive character creator ever, and then you can't do anything other than predefinied empty minigames. Its no fun to explore the world because there's nothing to do. You can't do anything cool. The world is dynamic on a global scale, but it has no substance on the small scale. You can't so much as eat all the fruit near a species nest to force them to move elsewhere.
Just my take on it. Good question