How many levels does it go to? I quit on 10. I know you need to beat 8 for your flight badge. I was surprised to not find any leaderboard after finishing that many levels too.

I tend to quit after level 8 for each craft, since that's all that's required for the badges.

Don't think there's much point in going further, unless you're simply trying to push your endurance levels! :-P

It never ends as far as I know. They do get harder and harder though. If I remember right I once went to level 16. And keep in mind that no game from that era really had a leaderboard, there wasn't any realistic way to maintain it. The Internet wasn't much of anything in 1993 after all and anyone who did go online tended to have to pay by the minute to do so via a modem.

The leaderboards are an offline thing referenced by the guide (which I still have). I seem to remember beating it once. I think the last level required almost all energy to engines and avoiding lasers.