Quoted from Bublehead:

After playing an F-ton of it during the Pin Expo Flip’n Out tournament back when it was the newest NIB you could buy, the consensus by everyone in our little group of 7 players (including Rick Stetta) was this title should have been called Misery Castle. Biggest gripe we had was the gaping left hand kickback outlane which was not enabled at the beginning of the ball. It was as if the left outlane was stuck on “super suck” mode. We did not find it very fun to play. Just my $0.02

Quoted from MattElder:

Agreed on the point that whatever he was playing had early code, perhaps not even what they were supposed to leave the factory with. Crap got rushed out for Expo play a lot back then. Who knows. But yeah, ball save is always on at start of ball.
Are far as the revision 3 code goes, it's been out there for a long time, it was more a matter that some of us that had it didn't know that others *didn't have it*. I've had my MC since 2007, and it had it already. I'm not so sure that it didn't leave the factory with it, but of course I don't know for sure.
At any rate, it's a pretty cool game. The music really gives it something extra. My biggest gripe is the lack of a feed for the upper left flipper (aside from the secret door eject).

Quoted from MattElder:

Of their released games, my favorite seems to alternate between Mystery Castle and Pistol Poker. But I really love my Slam-N-Jam proto. If that game had made it to production it would've been a hit. Williams even had an interest in buying the rights to it when Alvin G closed up. It's really fun, even with super duper early code.